Tutorial: Cryo-preservation
Transgenic Mouse Core Facility
The term cryo-preservation consists of the Greek word cryo (meaning »cold«) and »preserve« (to maintain, save, store). Cryo-preservation or cryo-conservation is a process to freeze and store cells and tissue. These can be stored (cryopreserved) in liquid nitrogen for years at a temperature of minus 196 degrees Celsius without becoming damaged or ageing. Here we show tutorials of two established techniques currently in use at our facility.
Slow programmable cryopreservation of mouse embryos (slow freezing)
Slow freezing is a well-established and probably the most used technique to freeze cells. After adding a special cryoprotective agent to prevent the formation of ice crystals in the cells the material is cooled in steps under computer control to -196 degrees Celsius. This permits long-term cell storage as the biological processes in the cell are shut down.
Mouse embryo vitrification using cryovial adapters
Vitrification is a newer and much faster process of cryopreservation. The cooling is achieved by liquid nitrogen. Beforehand, however, the intracellular water is removed from the cells by adding certain solutions, so that the formation of cell-destroying ice crystals is prevented. Compared to slow freezing, this method requires a lot of experience of the experimenter.