Cryopreservation of Animal Germplasm

Cryopreservation of animal germplasm is to preserve the germplasm at a very low temperature (-196 ℃) so that it could survive for a long time because its metabolism was inhibited.Sperm and embryos as well as oocytes of many species were successfully cryopreserved since 1949.The number of species whose germplasm could be cryopreserved is increasing to improvement of the technology of cryobiology.However,there are still problems or difficulties for the cryopreservation of animal germplasm,such as low fertile ability of the germplasm,especially most of mammalian oocytes,after cryopreservation.Further study on the mechanism of cryopreservation,finding a better protocol and reducing the cryoinjury are crucial to cryopreservation of animal germplasm.The present paper describes some of the advances in the cryopreservation and outlines the relative merits and limitations as reference for the researchers in this field.