Cryopreservation is the technique in which the biological materials such as cell, tissues, organelles, etc. are preserved at extremely low temperatures, commonly at -196℃, in liquid nitrogen. All the biological activities stop at such low temperatures that leads to cell death and degradation of DNA. This makes it possible for storing the viable cells and other biological materials.
The intracellular ice formation might lead to the lysis of the cell membrane resulting in cell death. To prevent this, the freezing medium such as a diluter and a cryoprotectant compound is used.