Fig. 1

An overview of the mechanisms of cryopreservation and CPAs. Cryopreservation utilises either slow cooling, in which the sample is frozen at a controlled rate to allow water to flow out of the cell and prevent intracellular ice formation, or vitrification in which a high freezing rate and/or high CPA concentration prevents ice formation in the sample. Ice growth can be further controlled by ice nucleation inhibitors, controlled ice nucleation, ice growth inhibitors or ice recrystallization inhibitors. Devitrification occurs when a vitrified sample is warmed too slowly, resulting in ice formation. Apoptosis inhibitors may also be utilised to prevent cells from dying after cryopreservation from stress-induced apoptosis