“Cryopreservation is the technique of freezing cells and tissues at very low temperatures at which the biological material remains genetically stable and metabolically inert, while minimizing ice crystal formation. In general, when a tissueis subjected to low temperatures, ice crystals will eventually form. These crystals may disrupt the cell membrane leading to the death of the cell.The goal of cryopreservation is to replace some of the water with other compounds that will not form large crystals when frozen. The most commonly used replacements are DMSO (dimethyl sulfoxide) and glycerol. These are mixed into a solution with media or serum in which cells are suspended and placed in a liquid nitrogen freezer. As the media begins to freeze, the salt concentration outside the cells will become greater than that in the cells and water will leave the cells to be replaced by the cryopreservative”.