Freezers, Laboratory, Cryogenic
Definition : Laboratory freezers designed for tissue-sample storage (e.g., ovum, embryo) at temperatures below the point at which most or all biological activity ceases (sometimes defined as the glass transition temperature of water), about -130 degrees Celsius (-202 degrees Fahrenheit). These freezers typically use liquid nitrogen as the cooling agent; some specially designed electromechanical systems are also capable of cooling at these temperatures. The products may be stored directly in liquid nitrogen, which provides a temperature of -180 degrees Celsius (-292 degrees Fahrenheit) or colder with minimal temperature fluctuations; or they may be stored in the vapor phase above the liquid nitrogen at a temperature of about -140 degrees Celsius (-220 degrees Fahrenheit). Storage in the vapor phase decreases the risk of cross-contamination among the stored products. Tissue (e.g., ovum, embryo, bone, cornea) may be stored for extended periods, typically several years.
Entry Terms : "Controlled Rate Tissue Bank Freezers" , "Freezers, Bone" , "Freezers, Eye Bank" , "Tissue Bank Freezers" , "Cryogenic Freezers"
UMDC code : 22070