chilling injury and cold shock
The first challenge in cryopreserving cells from homeotherm (warm-blooded) animals is in
cooling the cells below body temperature. Cells may be damaged by very rapid cooling
(cold shock) or be damaged by low temperature per se (chilling injury). Behaviour and function of membrane lipids and proteins may be affected by temperature. For example, membrane lipids that are normally in a liquid crystalline state may solidify at non-physiological
temperatures, which can change their function and begin processes such as cryocapacitation of the production of reactive oxygen species that increase damage to membranes.
Decreasing the temperature may cause an imbalance in cellular processes because the rate
of one process may be affected more strongly than that of another. One example is the
disintegration of the metaphase spindle of oocytes caused by a change in the dynamic
equilibrium of the association/dissociation of the tubulin filaments.