Cryopreservation

Cryopreservation is a process where cells or whole tissues are preserved by cooling to low sub-zero temperatures, such as (typically) -80°C or -196°C (the boiling point of liquid nitrogen). At these low temperatures, the biochemical reactions that would lead to cell death are slowed or stopped. The cells being preserved, however, are often damaged during the approach to low temperatures or warming to room temperature.

Two phenomena which cause damage to cells during cryopreservation are solution effects and intracellular ice formation. Solution effects are caused by concentration of solutes in non-frozen solution during freezing. The mechanism of cell damage due to intracellular ice formation is not well understood.