Cryopreservation of Bovine Embryos

© 2015 John Wiley & Sons, Inc. The utilization of embryo cryopreservation has become an integral part of the technique of embryo transfer, particularly the commercial application in the bovine embryo transfer industry. There are generally two types of procedures used in the cryopreservation of bovine embryos such as slow-rate or "conventional" cryopreservation and vitrification. Vitrification refers to the solidification of water as a glasslike structure without the formation of ice crystals. Regardless of the cryopreservation method used, the selection of embryos to be cryopreserved is always a major factor influencing the success of the procedure. It is important to realize that many of the differences in morphological characteristics that constitute the embryo grading criteria are amplified by the freeze-thaw process. A cryoprotectant is defined as any substance that aids in cell survival during freezing and thawing.