Wednesday, June 04, 2008

Hoods, Cabinets, and Glove Boxes at Microscopes.com Researchers very often need to use laboratory enclosures to be protected from their projects. The nature of the experiment itself will determine what kind of enclosure is necessary. A chemical hood (fume hood) is used if the researcher is working with volatile or dangerous chemicals, or the chemical reaction produces dangerous fumes. A ducted hood sends the dangerous fumes to the atmosphere. A recirculating hood filters the fumes from the air and send the air back into the laboratory. A biosafety cabinet is used when the scientist is working with biohazardous material. A level I biosafety cabinet recirculates air in the hood through a HEPA filter. Some of the air stays in the cabinet and some is exhausted into the lab. The air in the hood is carried across the project toward the back of the hood to protect the worker. A level II biosafety cabinet vents the filtered air to the atmosphere. These hoods have glass doors which raise and lower to allow the experiments to be set up in the hood. While the experiment is being conducted there is an optimum height for the glass door which is indicated at the front of the cabinet or hood. There are many times when the project needs to be protected from the researcher or the atmosphere. When performing cell culture (tissue culture) a laminar flow hood is used. This type of enclosure passes air down the front of the hood and out to the room to keep contaminants from entering the cabinet. This is also the case with a PCR cabinet. There are times when a specific atmosphere is required such as research with anaerobic bacteria. In this case an airtight glove box is used along with a vacuum and special inlets to remove oxygen and moisture. In the case of moisture sensitive samples inert gases such as Argon or Nitrogen are used. Special transfer chambers on the side of these glove boxes allow the introduction of test samples without compromising the atmosphere inside. Microscope.com has a large line of Labconco laboratory enclosures to choose from.