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The resolution of a microscope optical system is dependent on many factors. Microscope objectives have many attributes. One common attribute is the medium in which the objective is designed to be used. It may be designated as dry, oil immersion, water immersion or glycerine immersion. By far the most common are dry and oil immersion. One of the factors that determines the ultimate resolution of the microscope is the NA (numerical aperture) of the objectives. Objectives with numerical apertures higher than 1.00 require a unified medium for the light rays forming the image to pass through. Since air nominally has a refractive index of 1.00 and the specimen slides typically have a refractive index of about 1.5, a 100X objective with an NA of 1.25 or greater can not perform to its highest capability( i.e. resolution). This is where oil immersion objectives come to the rescue! Among the many characeristics of microscope immersion oils is refractive index. For use in the visible spectrum most of these oils have a refractive index of approximately 1.515. If a microscopist places a drop of this oil between the objective and the specimen surface it effectively becomes part of the glass slide and unifies the refractive index of the system. In critical viewing situations, an oil immersion condenser can be employed. In this instance, the condenser is "oiled" by placing a drop of the same immersion oil between the condenser and the slide bottom thus unifying the refractive index of the entire system and improving the resolution to a much higher level than a "dry" system would allow. Many microscope manufacturers including Nikon, Motic and Unico include appropriate immersion oil as part of their microscopes.

I would like to introduce you to one of our newest family members; the Nikon E100 as you can see he's already a big hit with the rest of the world! The Nikon E100 comes in 4 different packages; the Educational Basic Binocular Phase Package, Educational /Biological Right Handed Upright, The Advanced Biological Binocular Phase, and the Biological Trinocular Phase Package! So, there are more than a few options for you to select from with our newest Microscope Family Member. The Nikon E100 is not big a bulky, it can fit into every laboratory and educational atmosphere without taking up much room at all. The optics are flat and distinct. With the phase contrast option as well as brightfield, the Eclipse E100 family of microscopes is a textbook choice for education and everyday laboratory use. So, now do you see what I see?

Okay, I am not speaking about how smart you are..What I am talking about is what type of light is right for your microscope! Tricked ya! Did you know that there are several types of electrical lighting for microscopes? Well, there are three; Tungsten, Fluorescent, and Halogen. Tungsten is the least expensive illumination. It is hotter and less bright than the other kinds. Fluorescent illumination provides cooler and brighter light than tungsten. This is beneficial when viewing slides for long periods of time or observing live specimens, such as protozoa. Halogen provides the very brightest illumination. The best microscopes have halogen lighting and most stereo microscopes with top lighting also use halogen lighting.

Microscope objectives are classfied according to many attributes. Field flatness, chromatic aberration, spherical aberration and working distance are some of the more common classification criteria. The most commonly available objectives are called achromats. These are also referred to as flat field objectives and are chromatically corrected at two wavelengths of light (usually near the red and blue ends of the visible spectrum) and one wavelength spherically (usually at midspectrum, i.e. green). The next most common level of microscope objective is called a planachromat. These objectives have the same chromatic corrections as an achromat but an additional optical element is added to enhance image flatness across the entire field of view. Plan-achromat microscope objectives may be included with higher quality microscopes for more critical examinations. Planapochromat objectives represent a much higher level of optic and are corrected at three wavelengths chromatically and two wavelengths spherically. Many microscope manufacturers offer several grades and types of objectives to satisfy many applications and budgets. The Nikon Eclipse series and the Unico Medical/Research instruments are two examples of companies that offer a selection of microscope objectives.

Okay, so you are wondering what I am getting at; well its Adaptive Immunity, In humans, and vertebrates in general, immune cells are so able to learn and improve immune defenses when they encounter the same microbe several times. This part of the immune system is called the adaptive immune response and this ability is called a “memory response”. Specialized cells work together to recognize a disease-causing microbe and they create targeted responses to the organism. The key to this response is the production of specific antibodies by the cells that are designed to specifically attack the microbe causing the threat. These responses will be “remembered” by the cells so that they can respond quickly the next time this threat is encountered. In particular NASA is interested in studying Drosophila’s innate immune response is similar to humans. One of the ways it is similar is the way cells recognize invaders. NASA scientists use some of the worlds best laboratory equipment to study other organisms like fruit flies. They use vibration plates, flasks to hold the fruit flies, petri dishes, microscopes, and laboratory consumables such as gloves. They study bacteria, fungi, and toll receptors of Drosophila's. Toll receptors sense infection both in humans and Drosophila's. The reason NASA scientists study to learn about how the immune system is affected by space travel. Something to think about if you are interested in the effects of spaceflight on humans!

When your college student goes back to school after the Holidays he may need to take a college microscope with him. From my experience most microbiology classes require up to 1000x magnification. Here are some microscopes which won't break your wallet and won't frustrate your college student. First is the Unico M250 compound binocular light microscope. This has great optics for the price. It magnifies up to 1000X and has a 1.25 NA Abbe condenser. Without a good microscope condenser to focus the light the student will not be able to see anything at higher magnifications. The Unico M250 also has a graduated mechanical stage, also necessary at higher magnifications. To save money you can order the monocular rather than the binocular. Better a good monocular microscope than a binocular microscope with cheaper optics. Another choice is the Konus Biorex 2 Biological binocular objective microscope. This also has a mechanical stage, a condenser, and magnifies to 1000X. Both of these microscopes are in stock and can ship right away. A microscope for college should be sturdy, have good optics, and reliable controls.

When it comes to realism, CSI Miami is right on! A little "in" on what's real in the CSI Miami Crime Lab. The young womans body on the shiny stainless steel autopsy table is fake. It's about the only thing that is not authentic in the "CSI Miami Crime Lab". Technical Adviser Elizabeth Devine explains "Everything in the CSI Miami crime lab is real laboratory medical autopsy equipment. "Our set decorators and designers work really hard to not only make beautiful sets, but also sets that are real," says Devine, a former Los Angeles County Sheriff's Department crime scene investigator and DNA lab supervisor. In the made-for-TV crime and DNA labs are $150,000 mass spectrometer equipment, $21,000 spectrophotometer, a $90,000 genetic analyzer, microscopes, centrifuges, pipets, pipette tips, and all kinds of laboratory consumables; such as gloves, centrifuge tubes, beakers, swabs, zipper close evidence bags and so much more that are the envy of many U.S. crime scene investigators. I have even witnessed while watching the show, some of the name brands of scientific instrumentation that we sell! Try Thermo Fisher Scientific! Watch the show and pay close attention you will see some familiar brands too!