serves to freeze and store cells or tissue at a temperature range often below -80 °C. Thereby, most cells are stored in the gas phase of liquid nitrogen in cryovials (vials) or cryobags 6, whereby the metabolic activity stops. After thawing, the cells can once again take up their typical physiological processes, presuming that the cells were not damaged through ice crystals thanks to fast freezing. Important factors for successful cryoconservation are, furthermore, extremely vital cells at the time of freezing, optimal freezing and thawing rates (generally -1 °C per minute when freezing and as fast as possible when thawing), a sufficient amount of cells, the suitable culture medium and the use of cryoprotectants. See cell banks.