Microscopes Blog

Differential WBC Count

Paul — Fri, 07 Jun 2013 20:13:39 +0000

A differential white blood cell count or differential WBC count can be used to determine which infectious disease is present in an individual. In 1883 Elie Metchnikoff puplished the phagocytic theory of immunity. He postulated that large cells in the tissue fluid and blood of animals were the first line of defense against foreign bodies. He stated that the larger cells were macrophages and the smaller ones were microphages. Neutrophils make up roughly 50-70% of the cells in blood, lymphocytes make up 20-30%, monocytes 2-6%, eosinophils 1-5% and basophils less than 1%. A normal white blood cell count is between 5,000 and 10,000 white blood cells per cubic millimeter. High white blood cell counts are referred to as leukocytosis. When counts fall below 5,000 leukopenia is said to exist.

Methicillin Resistant Staphylococcus Aureus

Paul — Fri, 24 May 2013 20:37:50 +0000

Methicillin resistant Staphylococcus aureus is a bacterial infection caused by S. aureus that is extremely resistant to some antibiotics. Recently an elementary school in Chicago was shut down because several students were diagnosed with MRSA. S. aureus normally lives on the skin and in the nasal passages. The bacteria can cause infection if it enters through a cut, sore, or breathing tube. The infection can be minor such as a pimple or more serious involving the heart, lung or blood. Serious staph infections are more common in people with weak immune systems and people in hospitals and long-term care facilities. There are two types of MRSA infections: community associated and healthcare associated. Healthcare associated infections occur in people who have recently been hospitalized or had surgery in the past year. Community associated infections occur in healthy people who have shared items such as athletic equipment and razors and children in daycare facilities.

Slide Agglutination Test

Paul — Fri, 10 May 2013 19:02:35 +0000

The slide agglutination test determines whether or not a specific protein exists within a species. Many manufacturers of reagents for slide agglutination tests utilize polystyrene latex particles as carriers for the antibody molecules. By conjugating reactive antibodies to these particles, an agglutination reaction results that occurs rapidly and is much easier to see than ordinary precipitin-type reactions that are used to demonstrate the presence of a soluble antigen. The test reagent is a suspension of yellow latex particles sensitized with antibodies for coagulase and protein A. Reagents are used to provide negative and positive controls. Disposable cards with eight black circles printed on them for performing the test. The black background of the card provides good contrast for the agglutination reaction that occurs.

Serotypes

Paul — Fri, 12 Apr 2013 18:40:30 +0000

Organisms of different species differ not only in their morphology and physiology but also in the characteristics that make up their molecular structure resulting in different serotypes. The proteins, polysaccharides, nucleic acids, and lipids define the molcular structure of an organism. Some of the macromolecules such as proteins, lipoproteins, and nucleoproteins can act as antigens because when these molecules are introduced into an animal, they cause the formation of antibodies. In order to produce antibodies, the substance must be foreign to the host organism. The antigenic structure of each species of bacteria is unique to that species similar to our fingerprints. These unique characteristics allow each species of bacteria to be differentiated from the next.

Shigella

Paul — Fri, 29 Mar 2013 20:22:11 +0000

The Shigella are divided into four species: Shigella dysenteriae, Shigella boydii, Shigella Flexeri, and Shigella sonnei. Like the Salmonella, the four species are divided into a number of different serotypes. Serotypes are strains that have similar biochemical characteristics but differ in their antigenic composition. Various lines of evidence, including genetic analysis, suggests that the Shigella may be pathogenic variants or pathovars of Escherichia coli. Shigella affect only primate hosts and have a narrower range than E. coli. Shigella is of great medical importance due to its ability to cause gastroenteritis, bacillary dysentery, foodborne illness, and diarrhea in humans.

Intestinal Pathogens

Paul — Fri, 15 Mar 2013 18:14:04 +0000

The intestinal pathogens of the most medical importance are the salmonella and shigella and pathogenic strains of Escherichia coli. They cause gastroenteritis, bacillary dysentery, foodborne illness, and diarrhea in humans. Right now the taxonomic differences of salmonella are being revised. In the first edition of Bergey’s Manual of Systematic Bacteriology, Salmonella is divided into two species, S. choleraesuis and S. bongori. S. choleraesuis is divided further into six subspecies based on different taxonomic and nucleic acid differences. If you base the classification system on antigenic differences the Salmonella can be divided into 2500 different serovars or serotypes, most of them belong to S. choleraesuis. A serovar is a strain that has similar biochemical characteristics but differ in their antigenic composition. It is important to identify serovars in order to determine the identity of the pathogen causing outbreaks of Salmonella infections.

Nikon Eclipse E200

Paul — Fri, 01 Mar 2013 19:37:45 +0000

The Nikon Eclipse E200 compound microscope offers superior optics and high quality construction. This is one of the most widely used microscopes in veterinary clinics and doctor’s offices. Nikon’s Chromatic abberation-free infinity (CFI60) system provides an expandable platform for more advanced microscopy techniques that involve the use of CCD cameras and laser microscopy systems. This optical system also offers crisp clear images allowing users to increase the efficiency with which they view their samples. Its durable construction and price point makes it a perfect fit for biology courses at the college level. College courses put a lot of wear and tear on microscopes forcing durability to be a high priority microscope requirement. The E200 also provides a cost effective solution for more advanced techniques such as darkfield, phase contrast, fluorescence and simple polarizing. The Nikon E200 has proven to be a solid microscope solution in a wide range of environments from college level courses, medical laboratories, doctor’s offices and research laboratories.

Bacterial Cell Wall

Paul — Fri, 15 Feb 2013 20:37:43 +0000

The bacterial cell wall contains a common and important component called peptidoglycan, which is only found in prokaryotes. Peptidoglycan is a polymer of alternating n-acetyl-glucosamine (NAG) and n-acetyl-muramic acid (NAM) which are linked by a covalent bond. Each NAM contains a chain of 4 amino acids. This amino acid chain crosslinks the adjacent polymers of amino sugars forming a lattice network around the exterior of the cell. It is this lattice that determines the shape of the cell (coccus, rod, or spiral). The lattice diversity results from a bridge being formed from different amino acids within the lattice. For example Staphylococcus may have the serine and glycine amino acid form a bridge as opposed to multimpl glycine residues. The cell wall of gram positive bacteria is made of up of 90% peptidoglycan. Most gram positive bacteria have teichoic acid in their cell wall as well. This is what creates the overall negative charge.

Ultraviolet Light

Paul — Fri, 01 Feb 2013 19:37:00 +0000

Ultraviolet light also referred to as UV light can be used as a germicidal agent to sterilize surfaces where sensitive microbiology techniques are being performed. UV light is nonionizing short wavelength radiation that falls between 4nm and 400nm in the visible spectrum. In general, the shorter the wavelength the more damaging it is to cells which makes UV light more damaging than visible light or infrared light. Most bacteria are killed by UV light. UV radiation at 260 nm is most damaging because at this wavelength DNA maximally absorbs UV light. When DNA absorbs UV light pyrimidine dimers form. A pyrimidine dimer is a covalent bond formed between two adjacent cytosine or thymine molecules in a DNA strand. These dimers distort the overall structure of the DNA strand and prevent DNA polymerase from moving past the dimer. Genes downstream from the dimer will not be transcribed and essential proteins will not be formed. The ability of the organism to function normally will be affected by the formation of one dimer.

Slime Mold

Paul — Fri, 18 Jan 2013 14:00:00 +0000

Slime molds are Eukaryotic, heterotrophic microorganisms that exist in cool, shady, and moist areas. They are often found on decaying logs, dead leaves, and other organic material. They ingest their food similar to an amoeba by phagocytosis. The vegetative cells lack cell walls however when fruiting bodies are formed, cell walls are present in these structures. Slime molds are in the division Gymnomycota in the Kingdom Myceteae. Slime molds have characteristics similar to protozoans and fungi and can be classified as either. The life cycle of the genus Physarum starts with the plasmodium. This is a multinucleate structure and moves over its food by flowing its cytoplasm similar to the way in which an amoeba moves. Most species feed on bacteria and other small organisms. The organism will change from its plasmoidal stage and form a sclerotia. The sclerotia is a hardened structure that forms when environmental conditions are not favorable. Sporangia can form under unfavorable conditions as well and they are fruiting structures. Sporangia can then give rise to pear shaped swarm cells.

Antibiotic Resistance

Paul — Fri, 04 Jan 2013 19:48:00 +0000

Antibiotic resistance is the ability of bacteria to develop immunity to antibiotics prescribed to treat infections. Antibiotic resistance is one of the world’s most pressing health problems and must be dealt with immediately. Antibiotics do not treat illnesses caused by viruses such as the flu, bronchitis, sore throats, and some ear infections and therefore should not be taken in such situations. The overprescription of antibiotics offers bacteria the opprotunity to produce future generations of bacteria that are not killed by antibiotics. Natural changes that occur in bacterial DNA may offer the bacteria an advantage when the microorganism encounters antibiotics. Antibiotics may also offer dangerous side effects. Antibiotics should only be prescribed for bacterial infections. MRSA or methicillin-resistant-staphylococcus aureus is a bacterium that has developed resistance to antibiotics such as penicillins and cephalosphorins. MRSA is prevalent in hospitals, prisons, and nursing homes where people have weakened immune systems. The amount of research dedicated to antibiotic resistance is disproportionate to the effect is has on our society and health system.

Norovirus

Paul — Fri, 07 Dec 2012 21:42:00 +0000

Noroviruses are viruses that are transmitted via fecally contaminated water and food, person to person contact, aerosolization of the virus, and contamination of surfaces. The virus flourishes in the winter because people spend less time inside and are closer to one another. Nororvirus outbreaks occur often in semi-closed communities such as long-term care facilities, hospitals, overnight camps, prisons, and cruises. Norovirus outbreaks occur throughout the year however over 80% of the outbreaks occur during November and April. When there are new strains of the virus new outbreaks tend to occur. Almost 67% of all norovirus outbreaks that occur in the U.S. occur in long-term care facilitites. These outbreaks are of great concern due to the large number of individuals with weakened immune systems. Outbreaks in this environment can last up to months. Norovirus is the leading cause of all food-borne illnesses in the United States. Nearly 50% of all cases in the U.S. from 2006 to 2011 were caused by the Norovirus. Cruise ships are also hot beds for norovirus activity. Due to the close living quarters, shared dining areas and rapid turnover of passengers the norovirus can pose a severe threat to one’s health. It is resistant to many common disinfectants which is why it is able to remain on surfaces throughout the ship.

Influenza A (H3N2) Variant Virus

Paul — Fri, 23 Nov 2012 21:57:00 +0000

The influenza A (H3N2) virus is labeled as a variant virus because it normally circulates in pigs however it is found in humas as well. Influenza A (H3N2) variant viruses carry the (M) gene that was present in the H1N1 virus from 2009 and human cases involving this virus were first detected in July 2011. The viruses were present in U.S. pigs in 2010. From July to December of 2011 12 cases of the H3N2 virus were detected in the U.S. From January to September of 2012, 307 cases of the H3N2 infection were detected across 12 states. It is believed that these infections occured because of prolonged contact with pigs at agricultural fairs. There have been some cases where human to human contact spread the disease however there has not been a major outbread due to this type of contact. Scientist believe that sporadic outbreaks of this virus will occur due to human to human contact however they will not be sustained. The Centers for Disease Control reccomends covering your nose and mouth when you cough as well as washing your hands with soap and water frequently throughout the day. If soap is not available you can use an alcohol based hand sanitizer. If you become ill stay at home until your illnes is gone in order to prevent infecting your co-workers/classmates.

Fluorescence Microscopy

Paul — Fri, 09 Nov 2012 19:10:00 +0000

Fluorescence microscopy is a technique where a microscope uses fluorescence to create an image. A sample is illuminated by light of an excitation wavelength and it emits light of a longer wavelength which is collected by the objective. A filter cube is placed in the light path and is located above the objective. The filter cube consists of an excitation filter, dichoric mirror and an emission filter. Xenon arc lamps and mercury-vapor lamps are used as light sources. Light passes through the excitation filter and reaches the sample. The sample is tagged with a fluorophore which releases light in a specific wavelength range. This light then passes through the emission filter and reaches the eyepiece. The dichroic mirror reflects the excitation light while allowing the emission light to pass through. Prior to being viewed with a fluorescent microscope samples must be prepared properly. This may involve the immunostaining of cells. This is a process in which an antibody binds to a specific protein within the cell. A secondary antibody conjugated to a fluorophore may be used to bind to the primary antibody. It is the fluorophore conjugated to the secondary antibody that emits the light that eventually passes through the emission filter.

Post Flood Mold

Paul — Fri, 26 Oct 2012 20:06:00 +0000

Anyone who is a flood victim of hurricane sandy should be aware of the dangers of post flood mold in their residence. Molds are fungi that can be found indoor or outdoors. Some estimates state that there are up to 300,000 species of mold however the total number is unknown. Molds thrive in moist, humid, warm environments and reproduce by producing spores that are highly resistant to harsh conditions. The most common indoor molds are Cladosporium, Penicillium, Alternaria, and Aspergillus. The Institute of Medicine has found that there was sufficient evidence to link indoor exposure to mold with upper respiratory tract symptoms, cough and wheeze within healthy people. Mold exposure can also exacerbate asthma. If mold is found in your place of residence it must be removed immediately. One cup of bleach in one gallon of water will be sufficient to remove and kill the mold. The Environmental Protection Agency should be contacted if an area larger than 10 square feet is infected with mold. The flooding caused by hurricane Sandy will not only increase the probability of mold growth however it will also increase the growth of pathogenic bacteria.

Fungal Meningitis

Paul — Fri, 12 Oct 2012 18:32:00 +0000

A recent outbreak of fungal meningitis has affected 271 patients across several states who received contaiminated steroid injections. This outbreak has caused 21 deaths and is being traced back to the compounding pharmacy that prepared the spinal steroid injections. The specialty pharmacy has since recalled three lots of the drugs. The CDC and FDA have confirmed the presence of a fungus known as Exserohilum rostratum in unopened vials of the drug methylprednisolone. Laboratory testing on the other two lots that are thought to be contaminated continues. The CDC and various health departments etimated that 14,000 patients have received shots from the contaminated lots and roughly 97% of these patients have been contacted. Meningitis affects the membraneous lining of the brain and spinal cord. Early symptoms include headache, fever, nausea and dizziness. Some of these symptoms can take up to a month to disappear. If fungal meningitis is left untreated it can cause permanent neurological damage and death. paul n.

Student Microscope

Paul — Fri, 14 Sep 2012 18:57:00 +0000

What makes a good student microscope? There are many different types of microscopes on the market and with the holidays around the corner now is a good time to talk about what features make a good student microscope. You may see microscopes with mirrors beneath the stage however these types of microscopes are not recommended for students. A built in light will provide better illumination than a mirror thus contributing to the overall resolution of the optical system. A mechanical stage is also highly recommended for student microscopes as this gives the user more precise control over the movement of the slide. At higher magnifications one can easily move the specimen outside of the field of view by moving the slide with their fingers. A mechanical stage allows one to move the slide very short distances. Having coarse and fine focus controls is important as well. The fine focus control allows the user to sharpen the image to obtain better resolution. Finally, the fourth feature of a good student microscope is a binocular head. Viewing a specimen through a monocular head tends to lead to eyestrain. Manufacturers such as Konus and Celestron make microscopes well suited for students of all ages.

Salmonella Outbreak

Paul — Fri, 31 Aug 2012 19:00:00 +0000

Recently there was a Salmonella outbreak in 16 states that affected 105 people that originated from Mangoes taken from a Mexican farm. Mangoes under the Daniella brand name distributed by Splendid Products contained this bacteria and first caused an illness in Canada. Salmonella is a gram negative, non-spore forming, motile species of bacteria characterized by their rodlike shape. Salmonella can cause illness such as typhoid fever, paratyphoid fever, and foodborne illness. Laboratory tests for Salmonella involve the use of TSI agar which contains ferrous sulfate. This agar allows easy identification of Salmonella because they product hydrogen sulfide. The majority of salmonella infections are due to contaminated food. Salmonella must be ingested in large numbers to cause disease in heatlhy adults. The acidic nature of the stomach destroys the majority of ingested bacteria. When outbreaks such as this occur, each case is reported and the source of contamination can usually be traced back to its source. Produce is sold under specific lot numbers which are tracked to various grocery outlets.

West Nile Virus

Paul — Fri, 17 Aug 2012 19:03:00 +0000

The West Nile virus is spread by way of mosquitos biting infected birds then biting humans. It was first identified in Africa in 1937 and the first case in the U.S. occured in New York in 1999. Since then it has spread west throughout the U.S., into Canada and into the Caribbean. The virus has also been found in ticks however mosquitos are considered the most important host. Almost 80% of West Nile virus infections do not cause any symptoms. When symptoms do occur their onset is immediately after the infection. Symptoms can include fever, headaches, fatigue, and muscle pain. Mosquito saliva is a cocktail of proteins that can affect vaso constriction as well as other characteristics of the immue response. Scientists do not know what benefit the virus offers to mosquitos. There is currently no vaccine and the best method of prevention is mosquito control.

Differential White Blood Cell Count

Paul — Fri, 03 Aug 2012 18:54:00 +0000

A differential white blood cell count is used to determine the relative percentages of various types of cells within a blood sample. Elie Metchnikoff proposed the theory of phagocytic immunity at the Pasteur Institute in 1883. He stated that large cells in the blood stream are responsible for defense against bacterial infections. Neutrophils, eosinophils, basophils, lymphocytes, and monocytes are the five types of cells in the blood responsible for engulfing foreign bodies in the blood. Wright’s stain is used to make these cells more visible under the microscope. When these cells are not stained they are colorless structures. During a differential white blood cell count 100 cells are counted using a differential counter and the percentage of each type of cell is determined. Neutrophhils are typically the most abundant making up 50-70% of the sample. There are between 5,000 and 10,000 white blood cells per cubic millimeter in a normal white blood cell.

Slide Agglutination Test

Paul — Fri, 20 Jul 2012 19:28:00 +0000

Microorganisms of different species differ not only in their morphology and physiology but also in various components that make up their molecular structure. The proteins, polysaccharides, nucleic acids and lipids define the molecular structure of an organism. Some of these macromolecules act as antigens because they stimulate the formation of antibodies when introduced into an animal. The antigenic structure of each species of bacteria is unique to the bacteria and just like a fingerprint, it can be used to identify that bacteria. Some species of bacteria are physiologically identical yet have different antigens. These species are referred to as serotypes. The slide agglutination test can determine the antigens of a microorganism. This method involves placing a suspension of cells on a slide then adding antiserum containing antibodies specific to that antigen. If the cells agglutinate or form clumps then the unknown species can be identified. This method is used in the identification of Salmonella and Shigella that cause infections in humans.

Stereo Microscope

Paul — Fri, 01 Jun 2012 21:16:00 +0000

What is a stereo microscope? A stereo microscope is a microscope that allows the user to view objects in three dimensions. A stereo microscope mimics the way your eyes look at objects so you are looking at a true image. The more widely known compound light microscope is used to view specimens mounted on slides and provides the user with a virtual two dimensional image. For applications such as viewing stamps, rocks, coins, insects, and circuit boards a stereo microscope would be more applicable. Larger objects such as the ones previously listed require a larger working distance or the distance from the object to the front of the microscope lens. The working distance of objectives on a compound microscope can be as high as 30mm for a 4x objective and as low as .23mm for a 100x objective. The working distance of a stereo microscope can go up to 170mm. This allows the user to manipulate the object beneath the objective lens. Stereo microscopes make great gifts for young learners because you can immediately view objects under the microscope without having to prepare slides as is the case with compount microscopes.

Water Quality Testing

Paul — Fri, 18 May 2012 20:40:00 +0000

Water quality testing is vital to the prevention of disease caused by intestinal pathogens. The overall number of bacteria is not as important as the species of bacteria present in drinking water. Once sewage is treated it is released into the bodies of water that produce our drinking water. Therefore it is imperative that this water be tested for pathogens prior to being distributed to homes and businesses. Escherichia coli is a good test organism and is a good indicator of fecal contamination for two reasons: 1) it occurs in the intestines of humans and some warm-blooded animals and 2) it can be easily identified by microbiological tests. E. coli is referred to as a coliform, which means that it is gram-negative, anaerobic, non-endospore forming rods that ferment lactose to produce acid and gas. Lactose fermentation with the formation of acid and gas provides the basis for determining the total coliform count of water samples in the U.S. and designates water purity.

Bacterial Counts of Foods

Paul — Fri, 04 May 2012 21:07:00 +0000

The presence of bacteria in food does not mean that the food is spoiled or that it can cause disease. Some foods have high bacterial counts because bacteria are used in their production. Yogurt, sauerkraut, and summer sausage are produced by fermentation and all have high bacterial counts associated with their production. Post production treatments such as pasteurization will significantly reduce the numbers of bacteria present. During processing and preparation food can become contaminated with saprophytic which occur in the environment. These bacteria may not be harmful or pathogenic. Bacteria are naturally associated with some foods when they are harvested. Green beens and potatoes have soil bacteria associated with them when harvested. Milk in the utters of cows is sterile but bacteria such as Streptococcus and Lactobacillus are introduced during milking and processing because they are part of the bacterial flora associated with the animal.

Microbial Spoilage of Food

Paul — Fri, 20 Apr 2012 20:57:00 +0000

The microbial spoilage of food can occur because of carelessness in handling the raw materials before canning, equipment malfunction that results in undetected underprocessing, or defective containers that allow the entrance of organisms after the heat process. The spoilage of canned foods is almost enirely contained within bacteria that produce heat resistant endospores such as Clostridium botulinum. This bacteria produces botulism toxin which causes food poisoning. Once food has been canned it is exposed to high temperatures for extended periods of time. Heat resistant bacteria produce three types of food spoilage: flat sour, T.A. spoilage, and stinker spoilage. Flat sour pertains to spoilage in which acids are formed with no gas productsion. T.A. spoilage is caused by thermophilic anaerobes that produce acid and gases. Stinker spoilage is due to spore-formers that product hydrogen sulfide and blackening of the can and contents.

Bacterial Catabolism

Paul — Fri, 30 Mar 2012 18:27:00 +0000

Bacterial catabolism produces energy by using two different metabolic means: respiration or fermentation. In respiration ATP is produced by the engery created by a proton gradient that is formed across a cell membrane when protons are transported from the cytoplasm to the outside of the cell. As electrons are shuttled down an electron transport chain involving cytochromes the movement of protons to the outside of the cell is facilitated. This process is called oxidative phosphorylation and results in the reduction of oxygen to water. In fermentation ATP is produced by substrate level phosphorylation where intermediates directly transfer high-enery phosphates to ADP to synthesize ATP. In general, fermentation is less efficient in producing engery relative to respiration because metabolic intermediates are used as electron acceptors and most of the available energy is left in molecules that form the end products.

Digital Microscopes Make Great Gifts

Robin Prymula — Mon, 28 Nov 2011 20:35:00 +0000

Digital microscopes come in different forms. The professional digital microscopes have eyepieces and dedicated cameras.

There are microscopes which look like a regular compound microscopes but have an LCD screen instead of eyepieces and can also have their images sent to a computer.

There are hand held microscopes in which a slide can be placed; these must be attached to a computer.

There are microscopes which can be placed on top of the object to be magnified and are also connected to a computer.

And there are hand held microscopes which have an LCD screen and need no computer.

Supposing you already have a microscope and wish to make it digital: Add an eyepiece microscope camera. As long as your microscope is DIN standard an eyepiece microscope camera will fit.

Digital Microscopes Make Great Gifts

Robin Prymula — Mon, 28 Nov 2011 20:35:00 +0000

Digital microscopes come in different forms. The professional digital microscopes have eyepieces and dedicated cameras.

There are microscopes which look like a regular compound microscopes but have an LCD screen instead of eyepieces and can also have their images sent to a computer.

There are hand held microscopes in which a slide can be placed; these must be attached to a computer.

There are microscopes which can be placed on top of the object to be magnified and are also connected to a computer.

And there are hand held microscopes which have an LCD screen and need no computer.

Supposing you already have a microscope and wish to make it digital: Add an eyepiece microscope camera. As long as your microscope is DIN standard an eyepiece microscope camera will fit.

Educational Gift

Robin Prymula — Mon, 21 Nov 2011 22:44:00 +0000

This year your kids are old enough to want a gift they can learn from, a microscope. A good compound microscope will teach the skill of microscopy. Digital microscopes are great fun but unless there are eyepieces to look through the student is not learning how to use a microscope. Microscopy is a skill they will need if they are to go on to study the biological sciences. With a microscope you get what you pay for. The optics in a microscope will determine the price. Other important features are a fine focus, not just a coarse focus; a light source, not just a mirror; and a mechanical stage, not just clips. Binocular (2 eyepieces) is preferable to monocular all other things being equal. A trinocular microscope will be great if the student would like add a microscope camera to save the images. If a trinocular is beyond your budget choose a DIN (standard) microscope and a microscope camera can be exchanged for the eyepiece. A good microscope will be an investment which will last many years.

Bug Microscope

Robin Prymula — Mon, 14 Nov 2011 22:09:00 +0000

It’s that time of year again. You are looking for a gift that will last over time and be useful for many years to come. You are tired of plastic toys which are discarded a week after the Holidays. A stereo microscope or a dissecting microscope is the perfect gift for that young scientist in your house. A stereo microscope lets you look at rocks and bugs and stamps and coins and anything else you want to look at up close. A stereo microscope is good for young eyes because it produces a 3 dimensional image and does not reverse the image like a compound microscope(for slides). Make sure that the microscope you purchase will last and will be easy to use and it will serve your student for years to come.

Microscope Slides

Microscopes Specialists — Thu, 13 Jan 2011 13:35:00 +0000

Plain or frosted, polished edges or ground edges, beveled corners or not and prepared or blank. Microscope slides are the essential required accessory that you must have in order to use a compound biological microscope. Slides are typically made of soda lime glass or borosilicate glass but the trait that they share in common is that a good quality slide will be optically “flat”. What this means is that the thickness will not vary across the width and breadth of the slide so that it will be visually detected. The so-called standard slide is 75 mm x 25 mm and nominally 1 mm thick. These dimensions will be maintained within a micron or two and will never cause any distortion in the image of the sample or cause the microscope objectives to lose parfocality. High quality prepared slides will also adhere to these same dimensions. There are specialty slides such as those used in geology and petrography, but the issues remain the same in terms of getting quality samples. The only time flatness is not an issue is when the various forms of depression slides are used to make suspension preparations.

Phase Contrast Microscopy

Microscopes Specialists — Thu, 06 Jan 2011 13:32:00 +0000

There are many techniques that are used to enhance images in a compound biological microscope. One of the most common as well as one of the most useful is phase contrast. This technique was developed by Frits Zernike (a Danish physicist) in the 1930′s and he was awarded the Nobel Prize in physics in 1953 for this significant contribution to the field of optics. As light passes through a medium of varying density, a phase shift or contrast change occurs as a result of the retardation or slowing of the illuminating wave front. Z ernike developed a method to take advantage of this change. It allows one to view cells in liquid suspension without the addition of stains or other chemical additives that might alter the nature of the sample. The image may be further enhanced with the addition of a green filter since this is the color to which the human eye is most sensitive. This remarkable change in contrast is easily appreciated in the included illustration of two epithelial cells. A microscope equipped with phase contrast allows sample viewing in both brightfield and phase without any additional specimen preparation. Common applications of the phase contrast technique include the examination of spinal fluid, urine, naturally occurring water sources and any other solution in which suspended particulate matter is suspected or needs to be evaluated..

HPLC Method Development

Robin Prymula — Mon, 27 Dec 2010 17:41:00 +0000

Trial and error is not the only way to develop an HPLC Method. There is simulation software available for method development. This software will save time by simulating changes in the chromatogram due to changes in mobile phase polarity, column particle size, column length, or solvent strength. Are you having trouble resolving two peaks? Do you normally deal with a difficult sample matrix? HPLC simulation software can help save time as the simulation take seconds to run the chromatograms rather than the 2 to 10 minutes normally required for each sample injection. The Molinar Institute offers their DryLab software. You can find other method development software at HPLCweb.com

Microbial Spoilage of Canned Food

Paul — Fri, 24 Dec 2010 23:02:00 +0000

Microbial spoilage of canned food occurs when heat processing fails to meet standard requirements. This can occur because of home canning of foods or carelessness in handling the raw materials before canning which results in a high level of contamination that ordinary heat processing may not control. Spoilage can also occur when defective containers permit the entrance of microorganisms after the heat process. Bacteria can cause heat resistant endospores which results in the spoilage of commercially canned foods. The processing of low-acid foods is over particular concern because Clostridium botulinum thrives in this environment and causes botulism food poisoning. There are three types of spoilage: flat sour, T.A., and stinker spoilage. Flat sour pertains to spoilage in which acids are formed with no gas production. T.A. spoilage is caused by thermophilic anaerobes that produce acid and gases in low-acid goods. Cans swell and sometimes burst. Stinker spoilage is due to spore formers that produce hydrogen sulfide and blackening of the can.

Microbiology and Microscopes

Microscopes Specialists — Thu, 23 Dec 2010 13:54:00 +0000

Microbiology is the study of small, living, primarily unicellular organisms. Collectively they can be referred to as microbes and may be bacteria, fungi or other single cell life forms. A common feature to all is that they are quite small and always invisible to the naked eye and therefore are viewed only with the aid of a compound microscope. They can be as small as 1 micron ( a forty-millionth of an inch) and can be as large as 15-20 microns. A hobbyist interested in learning about microbes will require an oil immersion lens usually of 100X magnification to be able to see them with a high degree of resolution. In the case of unstained samples, a phase contrast accessory will also improve image quality. Many beginning microscopists prepare slides of pond water as an initial source of many fascinating examples. Any serious microscopist, whether amateur or aspiring professional will surely want to own an instrument with this capability.

Nervous System: CNS Part II

Microscopes Specialists — Wed, 22 Dec 2010 12:00:00 +0000

The human body’s Nervous system is composed of three major organs: brain, spinal cord and nerves. These three organs are divided into two systems. The Central Nervous System is composed of the brain and spinal cord. The CNS function is to receive impulses from the body, process the information and respond with an action. This system is divided into four sections: Cerebrum (see Part I), Cerebellum, Diencephalon, and Brain Stem.

The Diencephalon, is located below the cerebrum and houses two of the most important functions of the brain within the Thalamus and Hypothalamus. The thalamus relays impulses from the eyes, ears, and skin. It is also responsible for the perception of pain. The Hypothalamus is responsible for body temperature, appetite, sexual desire, emotions, and sleep. It is also responsible for autonomic (involuntary) nervous, cardiovascular, gastrointestinal system functions. In addition, to the release of hormones from the pituitary gland, which functions include but are not limited to, growth, blood pressure, breast milk production and sex organ function.

The Cerebellum is the second largest portion of the brain. Its responsibility is to assist in coordinating voluntary body movements, maintaining equilibrium and balance.

Lastly, the brain stem is composed of three parts. The Middle Brain function is to act as a bridge for impulses between the brain and spinal cord. The Pons is the bridge the connects the Cerebellum to the rest of the brain. The brain is then connected to the spinal cord by the medulla oblongata. It is these divisions and subdivisions of impulses that make us uniquely human.

Bacterial Counts of Foods

Paul — Fri, 17 Dec 2010 18:23:00 +0000

The presence of bacteria in food does not mean that the food is spoiled however it is important, in some cases, to measure the bacterial counts of foods. Some food like yogurt, summer sausage, and sauerkraut are produced by microbial fermentation and therefore have high bacterial counts. Post production treatments reduce the total number of bacteria in these foods. Bacteria are naturally associated with some foods like when they are harvested. Green beans, potatoes, and beats have soil bacteria associated with them. The chalky appearance of grapes is due to yeasts that are naturally associated with them. Food can transmit disease very easily. The Centers for Disease Control estimates that 76 million per year in the U.S. become sick from foodborne illness. This illness usually results from bacteria or their toxins introduced to food products during processing, handling, or preparation. Botulism food poisoning results from ingesting a toxin produced by Clostridium botulinum when its endospores grow in improperly home canned foods. One can perform coliform counts to determine if bacteria is contaminated with fecal bacteria. In this method food must be mixed with water and put in a blender before it can be plated with agar.

Microscopes and USB

Microscopes Specialists — Thu, 16 Dec 2010 13:53:00 +0000

Microscopes are all around us and being used in almost every area of science and technology. Almost as common, is the use of microscope cameras to document an observation. Virtually all digital cameras (both still and video) incorporate the ability to communicate with a computer via USB (Universal Serial Bus). The symbol above is the universal identifier for USB communications. A microscope equipped with a digital camera can easily relay images to a computer via a standard cable that is normally supplied with with the camera. The cable connects the camera to the computer and imaging software will upload the images in seconds for both viewing and editing as well as measurement and analysis. These images can be used for publication, e-mailed to a colleague or just saved for future reference. Digital Cameras are available at various levels of resolution and price points from the hundreds to the thousands. A trinocular microscope with a photo port is the most versatile, but there are also eyepiece adapters for digital cameras as well that will fit many models lacking this feature.

Nervous System: CNS (Part I)

Microscopes Specialists — Wed, 15 Dec 2010 12:00:00 +0000

The human body’s Nervous system is composed of three major organs: brain, spinal cord and nerves. These three organs are divided into two systems. The Central Nervous System (CNS) is composed of the brain and spinal cord.

The general function of the nervous system is to: coordinate and control human body function; receive sensory input; make decisions; and orders body responses.

The CNS function is to receive impulses from the body, process the information and respond with an action. The CNS organ, the brain, is one of the largest organs in the body. The brain coordinates body activities and is the nucleus for thoughts, memory, judgment and emotion. The brain is divided into four sections: cerebrum, cerebellum, diencephalon, and brain stem.

The largest portion, found in the upper portion of the brain, is the cerebrum. The cerebrum is in charge of: thoughts, judgement, memory, associate and discrimination skills. The cerebrum is divided into two hemispheres, left and right, with four lobes: frontal, parietal, occipital and temporal.

Each lobe controls a specific function(s) within the human body. The frontal lobe controls speech, personality, and motor function. In turn, the parietal lobe receives and interprets nerve functions and interprets language. The occipital lobe controls vision; while, the temporal lobe controls smell and hearing. Although, all four lobes are in the same organ, the functions of each subdivision are unique and work interchangeable to make us wonderful human.

Microscope Slides

Robin Prymula — Mon, 13 Dec 2010 16:16:00 +0000

A microscope slide and a coverslip (cover glass) are all that is needed for an examination of pond water using a slide microscope. For the beginning and intermediate observer any microscope slide and coverslip will work. There are specialized slides which are optically flat or specially treated for tissue adhesion for the professional microscopist. For beginners or teachers prepared slides are a good introduction to the types of things which are studied using a microscope. The Meade #9o4 25 piece prepared slide kit has a good sampling of various types of plant and animal tissues. If you are interested in a particular line of study such as cell reproduction and development or human and animal parasites the Konus prepared slides will help the student or the teacher focus on the subject. If you are buying a microscope for the student for the first time, remember the blank slides, the cover glasses; and some prepared slides for instant observation.

Reductase Test

Paul — Fri, 10 Dec 2010 19:26:00 +0000

The reductase test is used to test the presence of bacteria in raw milk. Milk that contains large numbers of active growing bacteria will have a lowered oxidation-reduction poetential due to the exhaustion of dissolved oxygen by microorganisms. The fact that methylene blue loses its color or becomes reduced in such an environment is the basis for this test. One mL of methylene blue is added to 10mL of milk in a test tube. The tube is then sealed with a rubber stopper and inverted three times to mix. It is placed in a water bath at 35 degrees C and examined at various times over the next 6 hours. The time it takes for the methylene blue to become colorless is the methylene blue reduction time (MBRT). The shorter this time is the the lower the quality of milk. An MBRT of 6 hours is good whereas an MBRT of 30 minutes means poor milk quality. Streptococcus lactis and Escherichia coli are strong reducers and are present at this temperature in raw milk. The main value of this test is that it does not require a high level of training thus reducing operating costs for the laboratory.

Microscopes & Microscopy

Microscopes Specialists — Thu, 09 Dec 2010 13:50:00 +0000

The world of microscopes and the science of microscopy date from the 1600′s. Microscopy has fascinated man from the first realization that small objects could be magnified and examined in minute detail. The “homonculus” was thought to be a complete being contained within a human germ cell as early as the 17th century and needed only the time to grow and mature to become a recognizable being. The search for homonculi may have been the earliest inspiration for the development of the modern compound microscope. So where can one go to learn about the development of microscopes and the art and science of microscopy? Fortunately that question is easily answered and resources abound with information from the most basic to the most advanced. A number of major microscope manufacturers sponsor well annotated and well documented web sites and while these may be a little biased in the instruments that are featured the information is nonetheless invaluable. Some of the best include MicroscopyU sponsored by Nikon, the Zeiss site and the Olympus site. So when you decide to enter this fascinating world and invest in a microscope, do some homework, get some basic knowledge and explore the microuniverse around us. Make an informed purchase at a price point you can afford. You may not discover a homonculus or an animolecule, but you are sure to be amazed by what is invisible to the unaided eye.

Endocrine System

Microscopes Specialists — Wed, 08 Dec 2010 21:05:00 +0000

The endocrine system is a system of glands that secrete hormones throughout the body. Hormones are important to the human function of the body because they influence metabolic rate; water and mineral balance; immune system reactions; and sexual functioning. There are several organs that make up this system which include: adrenal glands; ovaries; pancreas; parathyroid glands; pineal gland; pituitary gland; testes; thymus gland; and thyroid gland.

The two main types of glands within the body are exocrine and endocrine glands. Exocrine glands release secretions into ducts that carry them outside the body. While, endocrine glands are ductless and release hormones directly into the bloodstream.

Here are a few glands and their functions within the human body.

The human body has two adrenal glands in which one is located above each kidney. Each adrenal gland is composed of both a adrenal cortex and adrenal medulla section. The adrenal cortex is responsible for the secretion of steroid hormones into the body. While the adrenal medulla is responsible for adrenaline.

The thymus gland is located in the mediastinum and apart of the immune system. The thymus gland secretes thymosin which is essential for growth and development of T-cells.

The thyroid gland is located on either side of the butterfly shaped trachea. The thyroid gland secretes thyroxine, triiodothyronine and calcitonin. Thyroxine and triiodothyronine adjust metabolic rate and regulate energy production. While calctonin regulates the level of calcium in the bloodstream.

School Microscope

Robin Prymula — Tue, 07 Dec 2010 00:23:00 +0000

So your student needs a microscope for high school biology class. If the student is looking at slides they will need a compound light microscope. There are 3 important things to look for. The first is good optics. With optics in microscopes you get what you pay for. A microscope with plastic parts and lots of magnification will be frustrating to the student. The second thing to look for is coarse and fine focus. At higher magnifications the student must have fine focus. The last thing is illumination. A mirror for illumination will not be sufficient for High School work. A light and a condenser to focus the light are essential for viewing the objects on the slides. Notice I did not say high magnification was important. Be wary of microscopes claiming 1500X – this level of magnification is not easily obtained even by the most sophisticated microscopes. 400X is sufficient for high school biology work. A good extra to make their work easier would be a mechanical stage.

The API Staph System

Paul — Fri, 03 Dec 2010 21:57:00 +0000

The API Staph System, produced by bioMerieux of Raleigh, North Carolina is a reliable method for identifying 23 species of staphylococci. This system consists of 19 microampules that contain dehydrated substrates and/or nutrient media. Except for the coagulase test, all the tests are importatnt in differentiation of Staphylococcus, Kocuria, and Micrococcus. The first step in this procedure is to make a saline suspension of the organism from an isolated colony. A staph strip is then placed in a tray that has a small amount of water added to it to provide humidity during incubation. Next, a sterile Pasteur pipette is used to dispense 2 to 3 drops of the bacterial suspension to each microcupule. The inocculated tray is covered and incubated aerobically for 18-24 hours at 35-37 degrees Celsius. Finally a seven-digit profile number is obtained and used to determine the identity of the organism. Final determination of the species can’t be done until one takes into account the source of the specimen, the colony characterisitics, and the antimicrobial susceptibility pattern.

Microscopic Field of View

Microscopes Specialists — Thu, 02 Dec 2010 13:00:00 +0000

One of the characteristics of a microscope eyepiece is the microscopic field of view commonly abbreviated FOV. The size of the FOV is expressed numerically in millimeters and is directly proportional to the combination of the eyepiece and the objective in use. The eyepiece, also referred to as an ocular, has a field stop as part of its design. The FOV is limited by this field stop and is defined as the diameter of the circle of light seen when looking into a microscope. The actual FOV is calculated by dividing the field number (FN) by the objective magnification. An eyepiece with FN=20 used with a 10X objective would have an FOV of 2.0 mm while an eyepiece where FN=26 would have an FOV of 2.6 mm. Widefield oculars have the advantage of showing a larger area of the sample at a given total magnification. Stereoscopic microscopes tend to offer a larger FOV even though their total magnification capabilities are less than compound microscope.

White Blood Cells to the Rescue!

Microscopes Specialists — Wed, 01 Dec 2010 11:59:00 +0000

Leukocytes or white blood cells are the key component of the human body’s immune system and on the first line of defense to protect the body against pathogens and foreign material. White blood cells are divided into three classes: granulocytes, lymphocyte and monocyte.
Granulocytes get their names from the granules found within their cytoplasm. Granulocytes make up at least half of the leukocytes within the human body. They are divided into three sub-classes: neutrophils, eosinophils and basophils.
Neutrophils is the most common type of leukocyte within the body producing trillions per day within your bone marrow. These cells are in constant reproduction because their life span is less than a day. Neutrophils are most attracted to foreign material, bacteria and inflammation. Upon siting a foreign invader the neutrophils will engulf it and use enzymes and other chemicals from its granules to kill it. If there is a surplus of neutrophils clustered at a site to kill a foreign invader pus will form.
Eosinophils, a less common white blood cell, is attracted to parasites in the skin and lungs. While Basophils is attracted to inflammation and carries histamine. When histamine is “over” produced within the human body it causes allergies.
Lymphocytes are the second largest class of white blood cells They are divided into two classes: B and T.
B-Cells mature in bone marrow and mature into plasma. B cells are attracted to pathogens and form antibodies. Once a pathogen is sited, B cells clone themselves to produce antibodies to fight off the pathogen.
T-Cells mature in the thymus gland. T-cells can detect cells within the body that are carrying viruses and kill them.
Monocytes mature into macrophages by floating in the bloodstream and entering tissue. They are the largest, in size, white blood cell within the body. Most organs in the body have their own macrophage. The macrophages found within the lungs for example ingest dust, particles, and bacteria. They are also responsible for clean-up of other white blood cells, such as pus. For more information regarding the leukocytes and the immune system please visit: http://health.discovery.com/

Microscope Magnification Fun

Robin Prymula — Mon, 29 Nov 2010 16:57:00 +0000

How about a digital microscopes for the kids this year. When it comes to science for kids a digital microscope is one of the best tools for exploration. A digital microscope makes microscope pictures and short videos which can be used for reports for school or funny electronic greeting cards. Imagine the stuff you can put on your facebook page with microscope magnification. Bugs, rocks, fingers; anything small you wish to magnify can be put under a hand held digital microscope. Look for a microscope with 1.2 mega pixel imaging as this is the same as your computer screen. Celestron and Carson are some manufacturers who make these fun, useful tools.

Test Media

Paul — Fri, 26 Nov 2010 19:33:00 +0000

Some test media are designed to provide multiple test results. These include Kligler’s iron agar, which determines fermentation reactions for glucose and lactose and the production of hydrogen sulfide. Hydrogen sulfide is produced as a result of the breakdown of the amino acid cysteine. It contains .1% glucose, 1% lactose, peptone, ferrous salts, and phenol red as a pH indicator. This media is prepared as a slant and is inoculated by streaking the slant and stabbing the butt of the tube. This medium is useful in the differentiation of the gram-negative enteric bacteria. When only glucose is utilized the slant turns red and the butt of the test tube is yellow. The slant is red because glucose was degraded aerobically and the ammonia released from peptone utilization caused the aerobic slant to become alkaline. The butt of the tube is yellow because glucose was fermented anaerobically. Kligler’s iron agar is a good example of how one type of media can be used to test multiple characteristics in a given species of bacteria.

Microscope Eyepieces

Microscopes Specialists — Thu, 25 Nov 2010 13:35:00 +0000

Microscope eyepieces are the third basic optical component of compound microscopes. The other basic components are the objectives and substage condensers. Eyepieces derive from two basic designs, Ramsden and Huygenian. No matter the design, the important issue is the contribution that the eyepiece(s) make to the optical system that we call the microscope. The eyepiece, also referred to as the microscope ocular, takes the real primary image that is formed at the intermediate image plane and magnifies it so that the eye can view the resulting virtual image at the desired magnification. The total magnification is equal to the product of the objective and the ocular. Thus, a 4X objective combined with a 10X eyepiece produces a final magnification of 40X. Eyepieces come in varying powers with 10X being the most common. Other available powers include 5X and 20X. While the eyepiece does not contribute to the resolution of the primary image, it is important that it be of the same optical quality as the objective since an inferior quality eyepiece can degrade the image produced by the objective. Some objectives can also support accessory components such as pointers and measuring reticles. When purchasing a microscope be sure that the eyepiece(s) will support the ultimate purpose of the system.

LN2

Robin Prymula — Mon, 22 Nov 2010 16:16:00 +0000

Where can you buy liquid nitrogen? Your local welding supply should have it. Or an industrial gas supplier. You must use the proper dewar to transport the liquid nitrogen. A dewar is different from a thermos because it is designed to handle the extremely cold liquid nitrogen temperature (-196 deg C, -321 deg F) without cracking. Dewars are designed to vent which is extremely important. As liquid nitrogen expands from the liquid to the gas stage it will build up tremendous forces if not allowed to vent and an explosion could occur. LN2 has been more and more a part of the culinary world and more people who do not generally work with it are using it. In addition to the danger of explosion, a user will get burns if they come in contact with the liquid nitrogen. Purveyors of LN2 will not release it to customers without the proper container. However with the proper container there is no restrictions on buying liquid nitrogen. Liquid nitrogen is used in cocktails because it is cold enough to freeze ethanol which has a lower freezing point than water. LN2 is also handy for making ice cream almost instantly.

Hydrolytic and Degradative Enzymes

Paul — Fri, 19 Nov 2010 18:39:00 +0000

Bacteria use a variety of degradative and hydrolytic enzymes to degrade large macromolecules into smaller units that can be imported into the cell. Because of the presence of the cell wall, bacteria lack the ability to surround and engulf their food by phagocytosis. Amylases and cellulases degrade starch and cellulose into simple sugars that are then transported into the cell where they are metabolized. Proteases such as casein and gelatin degrade proteins and peptides into amino acids. Lipases convert triglycerides into fatty acids and glycerol. Bacteria also hydrolyze small molecules because they can then acquire carbon compounds. Tryptophane is split into pyruvate and indole by the enzyme trytophanase. The pyruvate is then metabolized however the indole accumulates in the growth medium. The accumulation of indole is the basis for a test that differentiates bacteria that produce tryptophanase from those that do not. The presence or absence of various hydrolytic and and degradative enzymes can be used to identify bacteria.

Microscope condensers

Microscopes Specialists — Thu, 18 Nov 2010 13:19:00 +0000

The condenser is one of three optical components that are common to most modern compound, upright brightfield microscopes. The other two are the objective(s) and the eyepiece(s). The condenser is located above the light source and below the specimen stage. The Abbe condenser, developed by Ernst Karl Abbe around 1870 is considered to be the progenitor of all modern condensing systems. A basic ABBE condenser consists of two lenses and an iris diaphragm. When properly adjusted, it produces an image of the light source at the specimen plane and since there is no color correction usually exhibits red and blue color fringes at the edges of the field of view. The sample is illuminated and the primary image of the sample is formed at the intermediate image plane. The condenser not only illuminates the sample, it also helps to optimize image brightness, contrast and evenness of illumination. Often a daylight blue filter is used along with the condenser to help the sample colors and/or sample stains to appear natural without any color shift or bias. Compound microscopes of all levels almost always incorporate a condenser into their basic configuration.

Osteoperosis

Microscopes Specialists — Wed, 17 Nov 2010 17:37:00 +0000

Osteoporosis literally means porous bone. It is described as the thinning of bone tissue and loss of bone density over time. There are several reasons a bone can become porous. As well as it can affect a certain demographics over another. Osteoporosis is more common in women than men and is generally caused when the body doesn’t create enough new bone and/or too much old bone is reabsorbed by the body. This lost of bone causes the bone to become weak and brittle, making the body more susceptible to fractures and breaks. In fact, the bones can become so weak that an innocent sneeze can cause a bone to break. The lost of bone density does not happen over night and in most cases by the time this disease surfaces with blatant symptoms, the patient is in advance stages of the disease.
Homeostasis also plays a role in osteoporosis. A link to this disease is a drop in the hormones estrogen, in women over 50, and testosterone, in men over 70. Caucasian women with a history of osteoporosis in there family have a greater than average risk of developing the disease. Please see list below regarding other risk and symptom information.

Risk Factors:
Chronic Rheumatoid Arthritis;
Chronic Kidney Disease;
Eating Disorders;
Corticosteriod medications every day;
Hyperpathyroidsim;
Amenorrhea;
Binge and Surplus amounts of Alcohol;
Hormone treatments for prostate or breast cancer;
Low Body Weight;
Smoking;
Too Little Calcium in Diet;
Family History of the Disease

Symptoms:
Bone pain or tenderness;
Fractures and breaking of bone easily;
Loss of height over time;
Kyphosis

*** For more information regarding this disease please go to http://www.nof.org/

Monoclonal antibodies

Robin Prymula — Mon, 15 Nov 2010 16:47:00 +0000

Antibodies which are cloned and specific to one antigen are called monoclonal. They are generally made from mouse spleen cells fused with myeloma cells and grown in a culture media. The mouse has been immunized with the molecule of interest, the antigen. The specificity of these antibodies is what makes them so useful. They can be designed to target antigens on cancer cells; this can trigger an immune response to that cancer cell. Monoclonal antibodies can also be used to deliver treatments such as radioisotopes or toxins specifically to the cancer cell. Monoclonal antibodies can be conjugated (linked) with pharmaceuticals for treatment of autoimmune diseases such as Crohn’s disease and rheumatoid arthritis. In immunohistochemistry antibodies specific to antigens on a tissue section are conjugated to a fluorescent compounds. When the tissue section is viewed under a fluorescent microscope the object of interested fluoresces. Monoclonal antibodies are also conjugated to enzymes such as horseradish peroxidase (hrp). These are used in immuno assays to detect antigens in solution.

Semmelweis and Hand Scrubbing

Paul — Fri, 12 Nov 2010 19:36:00 +0000

In 1846 and 1847 Ignaz Semmelweis discovered the importance of hand scrubbing at the Lying-In Hospital in Vienna. He was the head of obstetrics and noticed that the death rate due to childbirth fever was approaching 20%. He observed that medical students and doctors were delivering babies after being in dissection and autopsy rooms. These doctors were not washing their hands after being in these rooms. At the same time, babies delivered by midwives and nurses had a lower death rate. Semmelweis instituted a policy that required doctors to disinfect their hands with bleach prior to examining obstetric patients or delivering babies. As a result, the death rate was lowered to 1%. Today it is routine practice to wash one’s hands prior to the examination of a patient and to do a complete surgical scrub before surgery. The human skin contains a wide range of microorganisms. Some protect us from harmful bacteria by outcompeting them for space. Diptheroids are gram-positive bacteria that break down the oily substance in our hair. Staphylococcus epidermidis is non-pathogenic and lives on our skin. It survives by secreting substances that kill other species of bacteria.

Microscope Objectives

Microscopes Specialists — Thu, 11 Nov 2010 13:20:00 +0000

Microscope objectives are the heart and soul of the compound microscope. They are responsible for formation of the intermediate image that the eyepiece(s) then further magnify to produce the image that is ultimately observed, analyzed and/or photographed. Common microscope objectives are usually identified as achromats, plan-achromats and plan-apochromats. The criteria for these categories are well defined and well recognized. Achromatic objectives may account for as much as 90% of the objectives seen in everyday use. They are corrected for chromatic aberration (color anomalies) for two wavelengths of light, usually red and blue and one wavelength of light, usually yellow for spherical aberration. Achromats are readily available, inexpensive and quite useful for much of routine microscopy. They, can however, exhibit a lack of sharp focus at the edges of the field of view that we recognize as spherical aberration, but color rendition is acceptable. Plan-achromatic objectives address this lack of peripheral sharpness by incorporating additional optical elements that cause the entire visible field of view to be in sharp focus. They are somewhat more expensive than achromats, but the image improvement is worth the additional cost. Plan-apochromatic objectives offer the highest level of correction for normal brightfield microscopy. These objectives have a third color correction in the green wavelength where color vision is most sensitive and an additional wavelength of spherical correction. These additional design enhancements provide the most highly corrected brightfield images. While these objectives are the most expensive, they also provide the highest levels of sharpness, contrast and resolution for the most demanding microscopists. Microscope objectives usually have engraving on their barrels to indicate the level of correction as well as other useful information. Unmarked objectives can be assumed to be achromats. When shopping for a microscope, pay special attention to the description of the objectives to help evaluate the overall quality of the instrument you are considering and the tasks you want to accomplish with it.

Welcome to the Wonderful World of Sonography!

Microscopes Specialists — Wed, 10 Nov 2010 16:02:00 +0000

Sonography or ultrasound scanning is a procedure that uses high-frequency sound waves to produce internal pictures of the human body. Unlike radiology, which uses x-rays by ionizing radition to produce a still image, sonography utilizes sound waves to create real time imaging of internal organs and processes. An ultrasound is ideal because it is non-evasive and can be use to diagnose and treat medical conditions. Ultrasounds are most commonly know in the obstetrics field to monitor growth and development of human embryos/fetuses during the prenatal period of pregnancy. However, ultrasounds are used in a variety of different medical fields including but not limited to: cardiology, gastroenterology, neurology, urology and musculosektal diagnostics.
An ultrasound unit consists of several items including a console, computer, video display screen and transducer. The transducer’s function is to send out sound waves throughout the tissues of the body and listen for return echoes to create an image. The image is produced from the amplitude frequency and the time it takes for the echo to return from the patients body/tissue to the transducer. In order for the transducer to work effectively a water-based gel is applied to the part of the body being examined to eliminate air pockets between the skin and transducer.

Sous Vide Recipes

Robin Prymula — Mon, 08 Nov 2010 17:22:00 +0000

A circulating bath or a bath with an immersion circulator is the equipment needed for the cooking technique known as Sous Vide. The technique involves placing the food in a vacuum sealed pouch and bringing it to the desired internal temperature, or 1 degree above, quickly and holding there for extended periods of time. Since the temperature of the food is never above the serving temperature, it can be held at extended periods of time without degrading the texture. This technique is especially valuable for extended cooking of tougher meats but can be also used for fish and poultry. It is the uniform heating and precise temperature control which makes recirculating baths useful for the Sous Vide technique. Even though the food is not elevated to the higher temperatures used in conventional cooking, the extended periods of time the food is held at the lower temperatures brings down pathogens to a safe level. Charts are available which give the chef cooking times and temperatures for various types of food. These charts take into consideration the desired serving temperature and the size or thickness of the food. In a restaurant the food would be plated and sauced from the pouch maintaining the serving temperature. Commercially the food is chilled very quickly and either kept refrigerated or frozen. In this case it is very important that the food be chilled as quickly as possible so that any spores cannot become new pathogens. The book A Practical Guide to Sous Vide Cooking will aid chefs in this technique.

Antiseptics

Paul — Fri, 05 Nov 2010 16:49:00 +0000

Everyday, a variety of antiseptics are used to control and/or kill microorganisms. Hospitals disinfect areas using strong chemicals such as sodium hypochlorite, which is identical to houshold bleach. Doctors and nurses use alcohol to swab areas where a needle will be injected. Betadine is used on skin prior to surgeries to ensure that bacteria does not cause infection. Municipalities use chlorine to prevent the spread of bacteria in drinking water and chemical agents are added to food to prevent spoilage. Antiseptics are agents that inhibit or kill microorganisms on living tissue while disinfectants are more harsh and used on non living objects. Some disinfectants are referred to as sterilants or sporocides, which mean they destroy all microbial life including endospores. Ethylene oxide is an example of a sterilizer that is used to sterilize objects that can’t be exposed to high heat. Sanitizers, such as those used in the food industry, reduce microbial numbers to safe levels but do not eliminate all microbes. Agents that are bacteriostatic inhibit the growth of bacterial cells but do not kill them.

Filters and Microscopy

Microscopes Specialists — Thu, 04 Nov 2010 12:50:00 +0000

Microscopy is an art as well as a science. Once a specimen slide is placed on the stage of a microscope and brought into sharp focus, the microscopist must determine if the contents of the sample are being demonstrated in the best possible fashion. Many samples, especially in the world of life science are stained with organic or inorganic dyes to bring out as much detail as possible. Depending on the illumination source employed, the stain used and the skill of the microscopist

the rendition of the colors may be less than accurate. One way to correct for this anomaly is to use appriopriate filters in the light path. The general categories that these filters fall into include neutral density, absorptive and interference. Neutral density filters attenuate the strength of the illumination without changing the color of the light. This is important when a specific “color temperature” must be maintained in order for the specimen to exhibit correct color properties. Absorptive and interference filters work by either retarding or enhancing specific colors or color ranges in order to enhance the effect of the stain on the sample. Though they use somewhat different means to accomplish this, the end result is effectively the same. A good way to learn what filter is needed and in what strength is to experiment with familiar samples to gain an understanding of how different filters work. Brightfield microscopes apply filters to such techniques as phase contrast and fluorescence and use other filters to enhance specimen colors in cytological and histological sample preparations.

The Amazing Heart!

Microscopes Specialists — Wed, 03 Nov 2010 15:01:00 +0000

The Heart is one of the most vital and worked organs in the human body. It is important to understand the basic functions and importance of the heart because
Heart Disease is the leading cause of death in the United States with a overwhelming 2,000 deaths per day (1 deaths per 44 seconds)! In addition to knowledge of the importance and functions of the hearts, it is also important to know preventative measures to ensure that this vital pump is working at its best. For the purposes of this blog, I will focus on the functions of the heart.
The Heart is a striated involuntary muscle (cardiac) composed of three layers (from inner to outer): endocardium, myocardium, and pericardium. In addition to layers, the heart is divided into four chambers: right and left atrium and right and left ventricle. Each chamber is a one way system designed to not allow deoxgenated or oxygenated blood to return to its previously exited chamber. Therefore, in a correctly functioning body Blood does not flow backwards. Associated with this enter and exit system are four valves: tricuspid, pulmonary, mitral, and aortic.

The heart beats in two stages. Stage One: Right and Left Atria contract simultaneously pumping blood to the right and left ventricles to propel blood out of the heart.
Stage Two: The muscle than relaxes to allow blood to fill up the heart again. Lastly Noted: The right and left side of the heart have two unique functions. The right side of the heart collects deoxygenated blood and pumps it to the lungs to pick up oxygen and release carbon dioxide. The left side of the heart collects oxygenated blood and carries oxygen and nutrients throughout the cells in the body.

Splitting Light

Robin Prymula — Mon, 01 Nov 2010 15:29:00 +0000

In spectrophotometers, microscope systems, and other optical instruments beam splitters are used to split a single light beam into 2 paths. A beam splitter consists of 2 triangular prisms of clear optical material such as glass or quartz fused together on the diagonal to form a cube. The diagonal fused surface is covered with a half silvered mirror which is precisely applied to reflect half (or whatever percentage is required) of the light and transmit the other half. Plate beam splitters are also used where the glass plate is half silvered. A beam splitter is used in spectrophotometers to split the incident beam so part will go through the sample and part will be used as a reference. The sample beam intensity is compared to the reference beam and the background noise is subtracted. A comparison of the sample and reference beam also compensates for any drift in beam intensity. Beam splitters are used in many microscope optical systems as well. In fluorescence microscopes a dichromatic beam splitter is used. The dichromatic beam splitter separates the beams based on their wavelength allowing one wavelength to pass through while reflecting another.

Nikon Small World

Paul — Fri, 29 Oct 2010 18:49:00 +0000

The Nikon Small World competition is a microscopists opportunity for 15 minutes of fame. This competition is also for anyone who appreciates photography. This competition has been around since 1974 and is designed to recognize those involved in photography while using a light microscope. The competition is open to anyone with an interest in photography through a microscope and entries have been submitted from the U.S., Canada, Latin America, Europe and Africa. Both proffesional and hobbyists have won the competition. One may submit a photo of any specimen and can use microscopy techniques such as brightfield, phase contrast, polarized light, fluorescence, interference contrast, and darkfield, confocal and deconvolution. The entries are then judged by photomicrography and micrography experts who rate the entries based on things like originality and visual impact. First prize in this competition receives $3,000 towards the purchase of new Nikon equipment.

Stereomicroscopy

Microscopes Specialists — Thu, 28 Oct 2010 12:00:00 +0000

Stereomicroscopy is helpful in almost any endeavor requiring a long working distance and relatively modest magnification. Stereoscopic microscopes are commonly referred to as “dissecting microscopes” but their applications are much more diverse. Biology, botany and almost any other area of life science that you can think of has a need for a stereo microscope. But that is just the beginning. Geologists, gemologists, electronics assemblers (think circuit boards), minerologists, numismatists, philatelists, printers and archeologists are just a few of the non-life science professional and amateur observers who find stereos to be invaluable if not indispensable. One of the most common questions of new users is, how does a stereo work? The easy answer is “very well”! The scientific explanation is also straightforward and quite simple. A stereocopic microscope has dual optical paths, one for each eye, offset to one another at about the same angle as your eyes. This offset allows you to “see” in three dimensions through the microscope in exactly the same way as you see in three dimensions as you view the world around you. Stereoscopic vision works in much the same way as stereophonic sound (after all, your ears are offset too!). These microscopes come in two basic configurations. They either have fixed magnification(s) or a continuosly variable zoom configuration. Either way, the secret is in the offset optical paths that are the heart of stereoscopic vision. The next time you want to get up close and personal with a caterpillar, a leaf, a coin or a gemstone give a stereo microscope a try. You’ll be amazed at what you will see…

Salmonella

Microscopes Specialists — Wed, 27 Oct 2010 13:24:00 +0000

Salmonella is a gram negative rod shaped bacilli that can cause havoc and even death in mammals. Salmonella is named after Dr. Daniel E. Salmon, who with the aid of Theobald smith discovered this strain of bacilli. Salmonella is spread … Continue reading →

Halloween Fog

Robin Prymula — Mon, 25 Oct 2010 22:29:00 +0000

Want to know how to create Halloween Fog? Get your trusty dry ice machine and make some dry ice first. Don’t have a dry ice machine? Then go to your local welding supply, chances are they’ll have some dry ice. Now get a 9 x 13 metal cake pan and fill it with Acetone from the paint store(NO FLAMES OR LIT JACK-O-LANTERNS PLEASE!). Place your 1lb block of dry ice in the Acetone and watch the fog. the Acetone helps to lower the temperature of the dry ice so it creates more fog. Acetone won’t freeze in contact with the dry ice like water would.

The Kirby Bauer Method

Paul — Fri, 22 Oct 2010 20:46:00 +0000

The Kirby Bauer method is a laboratory technique used to determine the efficacy of a given antibiotic or antimicrobial agent. Paper disks containing specific concentrations of the antibiotic or antimicrobial agent are placed on the agar surface containing a lawn of bacteria. The chemotherapeutic agent then diffuses out, forming a concentration gradient. If the agent kills the test organism, there will be a zone around the disk where no growth occurs called the zone of inhibition. The zone of inhibition varies with the diffusability of the agent, the size of the inoculum, the type of medium, and many other factors. The recommended medium in this test is Mueller-Hinton II agar. Its pH should be between 7.2 and 7.4 and it is poured to a uniform thickness of 4mm in the petri plate. Innoculation of the medium is performed with a cotton swab from a broth culture. High potency disks are used that may be placed on the agar with a mechanical dispenser or sterile forceps. After 16-18 hours of incubation the discs are measured to the nearest millimeter and compared to each other.

Cells Need To Breathe Too!!!!

Microscopes Specialists — Wed, 20 Oct 2010 22:50:00 +0000

Cellular respiration is imperative in the process of gaining useful energy for cells. It is a process in which metabolic reactions covert nutrient molecules into ATP (adenosine triposphate) and then release waste products.
A key component in cellular respiration or oxidative metabolism is Oxygen (O2) and in turn Carbon Dioxide (CO2) removal. Most often the process involves the complete breakdown of glucose to CO2 and water (H2O). Please see equation:

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ENERGY

In the equation, oxidation occurs between glucose (C6H12O6) molecules and 6 Carbon Dioxide (6CO2) molecules, therefore causing a reduction in sugar (6O2) and 6 water molecules (6H2O).

Glucose has numerous amounts of energy and its breakdown of O2 and H2O (which are low energy molecules) releases it. This released energy will be used in the production and collection of ATP molecules.

Cellular respiration, although an important process, occurs slowly and gradually because its immediate release would cause huge energy loss and non-usable heat.

Gene Patenting

Robin Prymula — Mon, 18 Oct 2010 15:00:00 +0000

When we think of patents related to genetic material we think of the PCR process patented by LaRoche. There are actually over 3,000 to 5,000 patents on human genes and over 47,000 patents on inventions involving genetic material. Patenting naturally occurring substances which have been purified has been going on for over 100 years. The first patent was for Adrenalin in 1906, the next was Insulin in 1923. In the 1970s scientists began patenting methods involving genetic material – recombinant DNA. The Supreme Court decided that as long as the material was modified or isolated it could be patented. Controversy arose in 2009 when Myriad Genetics were granted patents for 2 gene sequences related to breast and ovarian cancer, BRCA1 and BRCA2. Opponents to granting these types of patents such as the ACLU worry that having to purchase licenses to research these materials my inhibit research, especially by universities. At this point no research institution has been sued for studying or using a gene for academic research which is patented by another entity. For more information see the Hastings Center, a research center for bioethics research.

Cell Wall and Lysozyme

Paul — Fri, 15 Oct 2010 16:40:00 +0000

Bacterial cells are surrounded by a cell wall that contains peptidoglycan, which is only found in prokaryotes. Peptidoglycan is a polymer held together by covalent bonds. A molecule made of four amino acids, a tetrapeptide, helps hold peptidoglycan together. Not all bacteria have the same tetrapeptide which accounts for the differences in shape. The cell wall of gram-positive bacteria is composed of 90% peptidoglycan in addition to teichoic acids. Teichoic acids are responsible for the net negative charge on gram positive cells. The cell walls of gram-negative bacteria are composed of a thin layer of peptidoglycan and an outer membrane that encloses the peptidoglycan. The outer membrane forms an additional permeability barrier in these organisms. Humans are born with non-immune factors that protect them from infection from bacteria. Lysozyme is one of these factors and is found in most bodily fluids like tears and saliva. Lysozyme can break down peptidoglycan which results in cell lysis and death.

Lucky Number 7

Microscopes Specialists — Wed, 13 Oct 2010 13:01:00 +0000

PH (Potential of Hydrogen) is a measure of acidity or basicity of a solution. Acidic liquids releases hydrogen into a solution and basicity removes it. PH is measured on a scale of 0 to 14, where 7 is considered neutral. Acidic liquids are categorized as having a pH less than 7. Base or alkaline liquids are categorized as having a pH more than 7. PH measurements have multifaceted applications, which include but are not limited to mathematics, chemistry, medicine, and food science. In the human body pH is extremely important to proper functionality of cells and organs. Human homeostasis is the regulation of the internal workings of the human body to ensure stability against external conditions. Acid-base homeostasis is a type of human homeostasis that ensures balance between acids and bases. Overall the normal pH level in the human blood is about 7.4, although different organs and cells have different pH levels that they must maintain for proper operation. For example, urine has a pH level of 6.8 and saliva of 6.5, while gastric secretions have a pH of only 1.0-3.5. Gastric secretion are highly acidic and is essential to the stomach for digestion. Even the smallest change of pH levels can cause averse affects on the human body. Imbalanced pH can cause everything from Osteoarthritis to Chronic indigestion; and in severe cases death. PH is usually measured using color changing pH strips, with a corresponding color chart that indicates pH levels.

Sterile Filtration

Robin Prymula — Mon, 11 Oct 2010 16:05:00 +0000

Bottle top filters and sterile receivers aid the researcher in preparing sterile solutions for their work. For example cell culture media must be prepared sterile. Many different membrane materials are available including Nylon, Cellulose Acetate, Cellulose Nitrate, and Polyether Sulfone (PES). Pore sizes available range from 0.2um to 0.8um. Various receiver volumes are available from 115ml to 1L. These tools for sterile prep can be purchased separately or as complete units. If a lab has limited access to an autoclave or if a microbiology class only has a few lab classes requiring sterile media preparation, these filtration units are the answer to efficient sterile filtration. Nalge Nunc, Whatman, Pall, Greiner Bio-One, and VWR all offer sterile filtration units in various volumes, materials, and pore sizes.

Osmotic Pressure and Growth

Paul — Fri, 08 Oct 2010 21:02:00 +0000

It is important for microbiologists to understand the relationship between osmotic pressure and growth of bacteria. Osmotic pressure exists due to the concentration of solutes dissolved in water. During the process of osmosis water moves from an area of high concentration to an area of low concentration. Because there is normally a high concentration of nutrients in the cytoplasm relative to the outside of the cell, water will naturally diffuse into the cell. A medium where the concentrations of solutes outside of the cell is lower than inside the cell is called hypotonic. The cell wall of the bacteria protects it against this pressure. When the concentration of solutes outside of the cell is the same as inside this is called an isotonic environment. When the concentration of solute outside of the cell is higher than inside the cell, this is considered hypertonic. Water diffuses out of the cell in this environment. This type of environment is used to preserve food because there is no water available for the cells to grow. Some bacteria known as halophiles require high concentrations of salt between 15-30%. Some bacteria such as Staphylococcus aureus can tolerate sodium chloride solutions of up to 11%.

Birefringence

Robin Prymula — Mon, 04 Oct 2010 15:00:00 +0000

Birefringence can be observed under a polarizing microscope or a microscope with a polarized filter. In normal light (or other electromagnetic radiation) the waves are random directions about the axis of the light wave. In polarized light the waves are all in the same direction.Picture from MicroscopyU website.

When polarized light is passed through an anisotropic* crystal the light ray is divided into 2 rays depending upon the polarization. The different paths these light rays take is called double refraction or birefingence. A polarizing filter on a microscope will isolate the polarized light and indicate that a birefringent material is present. The diagnosis of Gout is dependent on observing the birefringent crystals of Uric Acid in the sinovial fluid of the affected joint. The Unico H608 microscope includes a polarizer filter kit which aids doctors in the detection of Gout.

*Anisotropic – having a physical property which is directionally dependent. Wood is anisotropic in strength as it can be split easier along the grain than against the grain.

pH and Microbial Growth

Paul — Fri, 01 Oct 2010 18:24:00 +0000

It is important to understand the relationship between pH and microbial growth. The pH or hydrogen ion concentration affects proteins and other charged molecules in the cell. Each organism has an optimal pH at which point they grow best. If the pH value exceeds the optimal pH the solubility of charged molecules can be adversely affected and molecules can precipitate out of solution. The pH can alter the charge on amino acids and result in denaturation of the protein. Like temperature, microorganisms can be subdivided into groups based on their ability to grow at different ph values. Bacteria that can grow at or near neutral pH are classified as neutrophiles. Most bacteria are neutrophiles although many can grow over a range of 2-3 pH units. Bacteria that grow at acidic pH values are acidophiles and bacteria that grow at alkaline pH values are termed alkaliphiles. Thiobacillus thiooxidans can grow at pH 1 and it derives its envergy needs from the oxidation of sulfide. They then produce sulfuric acid that lowers the pH of the environment. True alkalinophilic bacteria can be found growing in environments such as high carbonate soils where the ph is 10 or above.

Microscopy and light

Microscopes Specialists — Thu, 30 Sep 2010 13:38:00 +0000

Microscopy is as much art as it is science. The microscopic world of “brass and glass” as it is sometimes referred to, is almost always a prisoner of the source of illumination. Sunlight, candlelight, incandescent light, fluorescent light, high pressure arc lamps and most recently LED illumination have all been employed to supply both compound and stereoscopic microscopes with the illuminating energy that brings the images of the samples we want to investigate to our eyes. In some ways, the science is the easy part. You focus a lens system on the desired sample and the laws of physics render a magnified image for eyes to study and appreciate. The art involves choosing the source of illumination to best suit your needs. Sunlight is usually regarded as the best source to observe specimens with the least amount of bias as to how their natural colors are rendered;however, sunlight is not always available. Incandescent tungsten sources tend to amplify yellows and fluorescent sources seem to favor the blue/green portion of the visible spectrum. Each source will exhibit some degree of color bias. In addition, there is the problem of heat, especially as it affects living samples on a slide or in a Petri dish or other sample container. In modern microscopy the tungsten/halogen light source is the current common denominator for normal brightfield viewing and is a very good compromise for good color balance and minimizing the effects of heat since the actual illuminating components are somewhat removed from the specimen itself. Many current microscopes also offer LED light sources which boast extremely long bulb life, good color balance and virtually eliminate any heat issues. LED sources can also be powered by battery packs where AC current is not readily available or may be undesirable. If you are examining a geological sample or sampling the water in your aquarium or local fishing pond, investigate your options as to available illumination cources for your microscope.

So You Lack a Membrane?

Microscopes Specialists — Wed, 29 Sep 2010 14:22:00 +0000

Prokaryotic cells are defined as cells that lack a membrane bound nucleus. There are two basic types: domain Bacteria and domain Archaea. Prokaryotics average 1.1-1.5 um in width and 2.0-6.0 in length. Because they are such simple organisms there are only three main components of structure: cell envelope, cytoplasm and appendages. In addition, there are four basic shapes associated with these cells: bacillus (rod-shaped bacterium); coccus (spiral-shaped bacterium); spirilla (long rods twisted into rigid spirals); and spirochetes (long rods twisted into flexible spirals). Prokaryotics although simple organisms, are very important to human body functions. Bacteria, for example, is necessary and helpful for healthy digestion within the body. Bacteria is also used in the production of cheese and milk consumed by humans.
There are also bacteria that are harmful to humans such as Streptococcus, a coccus shaped bacterium that can cause strep throat. Another example would be Mycobacterium Tuberculosis a bacillus shaped bacteria that can cause Tuberculosis. However, since bacteria are there own organism and not parasites, like viruses, they can be killed/treated with antibiotics. Bacteria can be seen and observed through a compound microscope.
*Picture from http://www.positive-healthy-living.com/good-bacteria.html

Immunofluorescense Microscopy

Robin Prymula — Mon, 27 Sep 2010 15:00:00 +0000

Fluorescence microscopy is a valuable tool in the study of cells and their biological activity. Immunofluorescence adds to the utility of this study by the specificity of the technique.

Antibodies to specific molecules in the cell are conjugated with fluorphores. When viewed under a fluorescence microscope with the appropriate filters only the specific molecule of interest is observed. Two antibodies may be necessary: The primary antibody is specific to the molecule of interest in the cell and may be from mouse or goat or chicken… The secondary antibody is conjugated to a fluorophore and is anti-mouse or anti-goat or anti-chicken…. This technique is called immunofluorescence. One application of immunofluorescence is the identification and separation of embryonic and pluripotent(undifferentiated) stem cells.

Image from www.biologie.uni-hamburg.de.

Temperature Effects on Growth

Paul — Fri, 24 Sep 2010 15:41:00 +0000

Temperature has a significant impact on the growth of microorganisms. They can grow over a broad temperature range that extends below 0 degrees C. to greater than 100 degrees C. There are four groups based on the organism’s temperature requirement. Psychophiles grow between -5 degrees C. and 20 degrees C and can be found in the arctic and antarctic ocean. Mesophiles grow between 20 degrees C. and 50 degrees C. and most pathogens fall into this class. Thermophiles grow between 50 degrees C. and 80 degrees C. The bacteria in this group occur in soils where the midday temperature can reach greater than 50 degrees C. or in compost piles. Hyperthermophiles grow above 80 degrees C. and occupy environments that are heated by volcanic activity where water is heated above 100 degrees C. No single organism is capable of growing over the entire temperature range. Each organism is classified by one of the temperature classes. Enzymes are directly affected by temperature and their activity is what determines whether or not an organism will survive at a given temperature.

So You Think You’d Like a Microscope

Microscopes Specialists — Thu, 23 Sep 2010 14:00:00 +0000

There are many reasons to want a microscope from simple curiosity about the “invisible” world around us to a real need based on furthuring ones education or a new job requirement. To most people, the term microscope refers to a common brightfield instrument such as the one illustrated. Within this realm are two general types commonly referred to as compound microscopes and stereo (dissecting) microscopes. This post will limit itself to the world of compound microscopes. These instruments have a useful total magnification range of about 40x to 1000x based on utilizing 10x eyepieces and objectives ranging from 4x to 100x. In order to achieve the best ROI (return on investment) the buyer must have realistic expectations as to performance, a budget to support those expectations and some idea of what part of the microscopic world they wish to explore. Under no circumstances should any of the “toy” microscopes be considered regardless of the claims made by the manufacturer/distributor. These are for young children and component quality and build quality are usually marginal at best. Entry level brightfield microscopes will require a minimum budget of $ 100-200 and will allow reasonable access to such areas as pond water examination, plant parts, pollen and other common items from the world around us. The best route is a little background education and help or advice from any resoursce available including friends, teachers, edcational web sites, etc.

Cytology: Part I

Microscopes Specialists — Wed, 22 Sep 2010 11:00:00 +0000

Cytology is the study of cells. The study of cells truly began to blossom in the 1830′s with the work of German biologist Matthais Schleiden, a botanist, and Theodor Schwann, a zoologist. Their contribution: all organisms are composed of cells. And with the the addition of a German physician, Rudolph Virchow discovery that all cells come from pre-existing cells, cytology was spawn.
Cytology continued to develop through the advancement of microscopes. Microscopes are needed to view cells, whose sizes measure from one micrometer to one millimeter. Structurally, all cells are composed of a cell membrane, cytoplasm, and a nucleus. However, as the organism gains complexity so does the cell’s components.
There are several different microscopes that are used in this study. Please see the table below for a few examples of microscopes you can use to examine cells.

Type of Microscope

Basic Information

Compound Light

· Focused by glass lenses

· Light is passed through sample

· Caps at 1000x magnification

o 500 times better than the human eye

· Resolution is 0.2µm

Transmission Electron (T.E.M.)

· Focused by magnetic lenses

· Electrons pass through sample

· Imaged on fluorescent screen

· Caps at 100,000x magnification

o 100, 000 times better than the human eye

· Resolution is 0.00002µm

Scanning Electron (S.E.M.)

· Focused by magnetic lenses

· Sample sprayed with a thin coat of metal

· Imaged on fluorescent screen

Lab Notes and Good Laboratory Practice

Robin Prymula — Mon, 20 Sep 2010 15:30:00 +0000

Laboratory notebooks are designed in accordance with GLP. Lab notebooks in the research laboratory must be auditable and are considered a legal document. Laboratory notebook paper must be acid free for long term storage. Lab notes must be able to be traced back to original data; therefore lab notebooks have unique serial numbers, numbered pages, and the pages are not removable. Many laboratories are leaving written lab notebooks behind and are using an electronic laboratory notebook, ELN. ELNs are software programs designed to be searchable and traceable. Many laboratory instruments are now designed to be used with ELN software. ELN software must be designed to maintain the integrity of original data. Safety protocols must be included to protect against manipulation or falsification of original data.

Good laboratory practice is the principles and guidelines for performing laboratory research and recording the research. The Organization for Economic Cooperation and Development, OECD, has developed the GLP guidelines. GLP is used in laboratories which generate data related to the hazards of chemicals in the pharmaceutical, cosmetics, agrochemical, food additives, and other industries where the public comes in contact with chemicals. GLP is also used in many other laboratories to ensure the integrity of the data generated. For more information on GLP see the OECD website.

Image from nih.gov

Ultra Violet light: Lethal Effects

Paul — Fri, 17 Sep 2010 17:14:00 +0000

Ultraviolet light has lethal effects on most species of bacteria and causes damage to all bacteria. Ultraviolet (UV) light is nonionizing short wavelength radiation that falls between 4nm and 400nm in the visible spectrum. The shorter the wavelength the more damaging it is to cells. UV light is more damaging than visible light or infrared radiation. UV light is routinely used to sterilize surfaces such as work areas under clean benches used for the innoculation of cultures. The lethal effects of uv light are due to its mutagenic properties. UV radiation at 260 nm is the most effective against microorganisms because DNA absorbs the most UV light at this wavelength. UV light at this wavelength forms pyrimadine dimers. These form when a covalent bond forms between two adjacent thymine or cytosine molecules in a DNA strand. Dimers cause the DNA to become deformed which does not allow DNA polymerase to replicate DNA strands pas the site of dimerization. Genes past this point can’t be transcribed.

Protein to the Rescue!

Microscopes Specialists — Wed, 15 Sep 2010 11:00:00 +0000

A molecule composed of one or more polypeptides is a protein. There have been over 100,000 proteins identified and as much as 50% of the dry weight of cells is composed of them. Therefore, the study and comprehension of proteins are invaluable to biology, the study of life and living organisms. Proteins have various functions within animals; which includes, metabolic, supportive, transport, defense, regulatory and mobility functions. In fact, proteins are so imperative to living organisms that tissue and cells can sometimes be identified by the type of protein they contain or produce. A good example of this is red blood cells. Hemoglobin is a type of protein specific to red blood cells; whose major function is to transport oxygen throughout the organism. Other functions and examples can be seen in the table below:

Metabolic Functions

Enzyme: catalyzes chemical reactions in cells

Supportive Functions

Keratin/Chitin: Provides structural function. Keratin makes up hair/nails in humans and Chitin makes up the exoskeleton of crabs, etc.

Transport Functions

Hemoglobin: Transport oxygen within red blood cells from the lungs of a human, for example, throughout the rest of the body.

Defense Functions

Antibodies: Prevents antigens from destroying and upsetting cells regulatory processes.

Regulatory Functions

Hormones: Messengers that influence the metabolism of cells

Mobility Functions

Myosin: Causes muscles to contract by allowing parts of cells to move

Fire Safety Diamond

Robin Prymula — Mon, 13 Sep 2010 15:00:00 +0000

Ever wonder what the hazard symbols in the diamond placards on the sides of tank trucks are telling us? The signs are notifying us of the possible chemical hazards posed by the contents of the truck. The blue portion of the symbol represents health hazards. The yellow portion represents reactivity such as a tendency to explode. The red is flammability. The white portion is for special hazards such as dangerous reactivity with water. The higher the numbers the more dangerous the chemical. Use of this hazard symbol has been carried into the lab. It appears on wash bottles and other chemical containers.

The standards for this symbol were developed and are maintained by National Fire Protection Association. The NFPA refers to this symbol as the “Fire Diamond“. The fire diamond was developed to inform emergency workers of possible hazardous materials. For more information about the standards used to develop this warning system please refer to the NFPA Website

Image from National Marker

Bacteriological Examination of Water

Paul — Fri, 10 Sep 2010 15:41:00 +0000

Bacterial examination of water allows municipalities to monitor and regulate the level of microorganisms in drinking water. In cities, treated sewage is released into the lakes, waters, and streams. These bodies of water are also where we obtain our drinking water. As a result of the threat of contaminated drinking water, microbiological tests have been developed to determine if water is safe to drink. These tests are focused on the the presence of one bacterium in particular, Escherichia coli. This organism lives in the intestines of humans and other mammals and if found in water, is an indication of fecal contamination. This organims can be easily identified making it ideal to test for. E. coli is referred to as a coliform, which is a gram-negative, facultative anaerobic, non-endospore forming rod that ferments lactose to produce acid and gas in 48 hours at 35 C. There are three tests used to determine if E. coli is present in water: the presumptive test, confirmed test, and completed test. If all of these tests have produced positive results, coliforms are present.

The Spirit Filled Move!

Microscopes Specialists — Wed, 08 Sep 2010 16:58:00 +0000

A thermometer by definition is an instrument used to measure temperature by expanding and contracting a liquid within the glass filled tube to indicate temperature and/or temperature changes. Traditionally, the liquid used to measure these changes was mercury. However, due to the potential health risk associated with mercury if cracked or broken, there has been a move by some to switch to an alternative liquid.What is that alternative? Alcohol. Spirit-filled or alcohol thermometers is a good alternative to mercury because it is less toxic and evaporates quickly if damage occurs. Spirit-filled thermometers can me made of various types of alcohol depending upon the manufacturer and temperature range. Alcohol thermometers have a maximum temperature range of -115°C to 785°C, which is the freezing and boiling point of alcohol respectively. Here is a chart to display max and min temperatures values associated with each liquid.

*Filling liquid	Abbreviation	Lower limit (° C)	Upper limit (° C)
Mercury	Hg	-38.5	+800
Mercury-thallium alloy	Hg/TI	-58	approx.+150
Gallium alloy	Ga	-0	approx. +1.200
Technical pentane	C5H12	-200	approx. +35
Ethanol	C2H6O	-110	approx. +100
Pentanol	C5H12O	-115	approx. +135
Toluene	C7H8	-90	approx. +100
Creosote		approx. -40	approx. +210
Petroleum	P	approx. -45	approx. +160
i-amyl benzoate	C12H16O2	approx. -40	approx. +220

*From http://www.instrumentationservices.net

If you are looking for a safe alternative to mercury thermometers and are not interested in digital, I would suggest investigating and investing in a spirit filled thermometer.

Ion Analysis

Robin Prymula — Mon, 06 Sep 2010 15:00:00 +0000

pH is not the only thing that can be tested with test strips. Chloride tests and Nitrate tests can be performed using test strips. Some of the other ions which can be tested are: Ammonium, Cyanide, Formaldehyde, Lead, Peroxide… Some of these tests are just strips, some come in kits with other reagents necessary to perform the test. These tests are a quick way to find out if the ion is present and at what approximate concentration. These tests area great screening tool if the ion being tested does not need to be known with high precision. They are also a great screening tool to determine dilutions levels needed for more rigorous testing. Let us here at microscopes.com know what ions you need to determine and we will help you find a test strip.

Occurence of Disease

Paul — Fri, 03 Sep 2010 19:00:00 +0000

Due to extensive media coverage it is important for us to understand the terms that define the occurence of a disease. The incidence of a disease is the number of people in a population who develop a disease during a particular time period. It is an indicator of the spread of a disease. The prevelance of a disease is the number of people in a population who develop a disease at a specified time, regardless of when it first appeared. Prevelance takes into account old and new cases to see how a disease affects a popuulation over time. If a particular disease occurs only occasionally it is called a sporadic disease. Typhoid fever in the U.S. is such a disease. A disease constantly present in a population is called an endemic disease such as the common cold. If many people in a given area acquire a certain disease in a relatively short period of time, it is called an epidemic. Influenza often achieves this status. A pandemic is an epidemic that occurs worldwide. Some researchers believe that AIDS is a pandemic. Scientists will rely heavily on advanced microscopes as well as other laboratory related technologies in order to keep up with the constantly evolving world of disease.

The World of Loupes

Microscopes Specialists — Wed, 01 Sep 2010 12:00:00 +0000

What is a Loupe? Loupes are small, simple magnifiers that are usually hand-held or attached to the side shields of protective eye wear. Loupes have been around for centuries and are used in various professions spanning from jewelers and watchmakers to dentist and surgeons.

Although, the overall diameter of a loupe’s lens is smaller and has a smaller field of view of than a standard magnifier, they are still the preferred instrument of magnification of professionals. Loupes are compact and usually provide just the right amount of magnification for professionals that use them. For example, dentist who want to examine a patients teeth more closely during a surgical procedure may use a loupe attached to a shield to get the detail needed. Another example is a watchmaker who has to work with small mechanical parts and need to see them in greater detail. Loupes are not just convenient tools for professionals, but also have practical applications. The most common application is usage during reading for those who have weaker eye sight or evaluating small print. So, if you are looking for a tool with just the right amount of magnification to get details on an object invest in a loupe!

Measuring Microscope

Robin Prymula — Mon, 30 Aug 2010 15:00:00 +0000

Measuring objects with a microscope is known as micrometry. Most good microscopes can be used as a measurement microscope or inspection microscope. The necessary accessories are an eyepiece reticle (reticule) and a stage micrometer. Eyepiece reticles are available from the manufacturer of your microscope. Some eyepieces are designed to allow a reticle to be added by the user. Some reticles must me installed by the manufacturer. Reticles can be a line scale, a grid, a series of concentric circles, or some other scale depending on the application. Reticles must be calibrated with a stage micrometer. Stage micrometers are available in English units (inches) or metric (millimeters).

First determine the diopter adjustment which brings the reticle in sharp focus for your eyes and write this down. This will be your diopter adjustment for future measurements. Place the stage micrometer on the stage and, using the appropriate magnification for your application, line up one of the long bars of the micrometer with the zero on the reticle. Look for another place where a reticle line exactly lines up with a micrometer line. The longest point at which this happens will make the factor more accurate. Divide the micrometer distance by reticle line number. This will be the number of microns (thousandths of an inch for English) for each reticle line at this magnification. Now the stage micrometer can be removed and your sample can be placed under the objective and focused. You know know the distance between each reticle line, the factor, and you may use this to measure your specimen. A more thorough explanation of this calibration process can be found on MicroscopyU

Plant Viruses and Viroids

Paul — Fri, 27 Aug 2010 20:44:00 +0000

Plant viruses are very similar in morphology to animal viruses and they have similar types of nucleic acid. Some plant viruses actually multiply inside insect cells. Viruses can cause diseases to may different economically important crops. Beans can suffer from the bean mosaic virus, corn and sugarcane are affected by the wound tumor virus, and potates are succeptible to the potato yellow dwarf virus. Plant viruses can cause symptoms such as color change, deformed growth, wilting, and stunted growth however some plants do not suffer from symptoms and are merely carriers of the infection. Plants are able to protect themselves from viruses due to their impermeable cell wall. Viruses typically enter through wounds or they enter by plant parasites such as fungi, nematodes, or insects. Some plant diseases are casued by viroids, short pieces of naked DNA, only 300-400 nucleotides with no protein coat. Nucleotides are paired so the molecule has a closed, folded, three-dimensional structure that prevents attack from enzymes.

Glassware to the Extreme!

Microscopes Specialists — Wed, 25 Aug 2010 12:11:00 +0000

Looking for a type of glassware to withstand even the coldest of cold or hottest or hot? Try Borosilicate or Pyrex glassware. Glassware composed of at least 5% boric oxide by definition is considered Borosilicate glass. In addition to the glass being able to withstand extreme hot or cold, it is also chemical corrosion resistant and able to withhold unstable chemicals.
Another name for Borosilicate glass is Pyrex. Pyrex was an exclusive name given to Borosilicate glass created by Corning. However, since its inception, Pyrex is now considered a genericized trademark.
This extreme glass is used in everything from glass cookware to laboratory glassware (flask, slides, bottles, etc). Although, like any other glass, Borosilicate glass is not unbreakable when dropped or quickly removed from an extreme temperature to another, it is more likely to crack than shatter. So, If you are looking for a type of glass to go the distance, consider Borosilicate glass!

Coverglass

Robin Prymula — Mon, 23 Aug 2010 14:00:00 +0000

A coverglass or a coverslip is used to cover a specimen on a glass slide for examination under the microscope. The coverglass flattens solid objects and creates a thin even film for wet mounts. Coverslips can be sealed to the slide using sealants like Sakura Tissue Tek OCT Compound. Microscope cover slips are standardized very thin optically flat glass. They can also be made of plastic and quartz. They are sized to fit within the dimensions for a typical glass microscope slide (25 x 75mm) typically 20 x 20mm. Cover glasses are standardized by thickness:

no. 0: 0.085 – 0.13mm

no. 1: 0.13 – 0.16mm

no. 1.5(1 1/2): 0.16 – 0.19mm

no. 2: 0.19 – 0.23mm

no. 3: 0.25 – 0.35mm

no. 4: 0.43 – 0.64mm

The thickness of the cover slip is very important. Most compound objectives are designed to work with the no. 1.5 cover glass (0.17mm). Highly corrected objectives are equipped with a correction collar to allow adjustment for changes is coverslip thickness..

Antimycobacterial Antibiotics

Paul — Fri, 20 Aug 2010 20:43:00 +0000

The cell wall of the bacterial genus Mycobacterium differs from the cell wall of other species due to the presence of mycolic acids. This genus includes dangerous pathogens such as those that cause leprosy and tuberculosis. Due to the difference in cell wall structure a different class of antibiotics, known as antimycobacterial antibiotics is required to fight infections. Isoniazid is an antimicrobial drug against Mycobacterium tuberculosis. This drug prevents the synthesis of mycolic acids. When isoniazid is used to treat tuberculosis it is usually administered simultaneously with other drug such as rifampin (also known as rifampicin) or ethambutol. This minimizes the development of drug resistance. Because the tubercle bacillus is normally found within macrophages or walled off in tissue, any antitubercular drug must be able to penetrate into these sites. Ethambutol is effective only against mycobacteria as it inhibits the incorporation of mycolic acid into the cell wall. This drug is used typically as a secondary drug to avoid resistance problems.

Luer Connector

Robin Prymula — Thu, 19 Aug 2010 19:26:00 +0000

What is a Luer connector?

Meltdown

Microscopes Specialists — Wed, 18 Aug 2010 12:11:00 +0000

Meltdown! After months and years of trial after trial, data upon data, and specimen after specimen… you go to your lab to check on your prize possessions… and the freezer is warm! Your heart drops. Your stomach churns. Panic sets in… years of data lost… forever!

You must be wondering why those prize possessions were not linked to an alarm. Although an alarm is not a major laboratory purchase, it is critical to long term storage.

Alarm technology has increased from just lights, bells and whistles when the temperature drops below your threshold to automatic phone dial as a secondary line of defense in notification. Some alarms even have the capability of reading temperatures from multiple freezers and auto-dialing multiple numbers.

So instead of John Doe walking into his lab and having a massive panic attack, he could have been notified when the temperature was low and the samples were still salvageable instead of destroyed!

Plastic Droppers

Robin Prymula — Mon, 16 Aug 2010 13:40:00 +0000

Bulb pipets are very useful for transfer of fluids such as samples, reagents, and stains. Also known as disposable transfer pipettes these tools are indispensable. The pipettes are made from polyethylene and are pliable but tough. They are available sterile and non-sterile. Manufacturers such as Samco (Thermos Scientific) and VWR offer many different draw volumes and tip design. Some of the options are fine tip, extra fine tip, long stem, extra long stem, large bulb, exact volume, and pipets specially designed for blood bank applications. There is a large choice in transfer pipets. Perhaps the procedure you’re using could be improved with the right transfer pipette.

TB-detecting microscope

Paul — Fri, 13 Aug 2010 17:16:00 +0000

Andrew Miller, a bright student from Rice University, may have created a TB-detecting microscope that could save researchers thousands of dollars. Typically a confocal microscope, costing close to $40,000 is used to view samples from infected patients however Mr. Miller’s microscope only costs $240. People who are infected with tuberculosis are typically in remote locations which increases the time it takes to perform the test and get results. With Mr. Miller’s microscope researchers will be able to perform this test in the field and provide results immediately. Mr. Miller wanted to create a microscope that could be used in developing countries where laboratories and/or electricty are not readily available. In a recent clinical trial 63 TB smears were tested with a fluorescence microscope and Mr. Miller’s microscope. The two microscopes showed similar results in 98.4% of the tests. Once approved, this microscope will make TB testing much more efficient.