Cryopreservation is the use of very low temperatures to preserve structurally intact living cells and tissues. Liquid nitrogen is an ideal cryogen (-196°C/-321°F) for keeping biological samples fresh for indefinite periods. The temperature at which frozen cells are stored has a major effect on how long they can be stored. Typically, the lower the storage temperature is the longer the viable storage period can be. The impact of having samples cross the glass transition phase (~-137°C) and go from liquid to a glass is enormous. For any biological sample it is critical that consistent storage occurs below glass transition.
Air Products has an extensive knowledge of the cryopreservation market and will be able to offer you the best solution for your needs.