Controlled Rate Freezers are necessary for the accurate, repeatable process of reducing temperature in accordance with a given or programmed protocol. Whilst many biological samples may be stored via mechanical freezers or freeze drying, viability for a large proportion is optimised, or ensured, by storage at liquid nitrogen temperatures. The process of freezing down samples using cryo protectants can be a complex one. Rate of cooling affects protectant concentration which in turn may affect the cells beings frozen. The aim of good cryo-preservation is to ensure maximum viability of samples.
Programmable freezers have: