Campus Units
Animal Science
Document Type
Article
Publication Version
Published Version
Publication Date
2011
Journal or Book Title
Journal of Visualized Experiments
Volume
54
First Page
2764
DOI
10.3791/2764
Abstract
Preimplantation embryos from cattle, sheep, and goats may be cryopreserved for short- or long-term storage. Preimplantation embryos consist predominantly of water, and the avoidance of intracellular ice crystal formation during the cryopreservation process is of paramount importance to maintain embryo viability. Embryos are placed into a hypertonic solution (1.4 – 1.5 M) of a cryoprotective agent (CPA) such as ethylene glycol (EG) or glycerol (GLYC) to create an osmotic gradient that facilitates cellular dehydration. After embryos reach osmotic equilibrium in the CPA solution, they are individually loaded in the hypertonic CPA solution into 0.25 ml plastic straws for freezing. Embryos are placed into a controlled rate freezer at a temperature of -6°C. Ice crystal formation is induced in the CPA solution surrounding the embryo, and crystallization causes an increase in the concentration of CPA outside of the embryo, causing further cellular dehydration. Embryos are cooled at a rate of 0.5°C/min, enabling further dehydration, to a temperature of -34°C before being plunged into liquid nitrogen (-196°C). Cryopreserved embryos must be thawed prior to transfer to a recipient (surrogate) female. Straws containing the embryos are removed from the liquid nitrogen dewar, held in room temperature air for 3 to 5 sec, and placed into a 37°C water bath for 25 to 30 sec. Embryos cryopreserved in GLYC are placed into a 1 M solution of sucrose for 10 min for removal of the CPA before transfer to a recipient (surrogate) female. Embryos cryopreserved in EG, however, may be directly transferred to the uterus of a recipient.
Copyright Owner
JoVE
Copyright Date
2011
Language
en
File Format
application/pdf
Recommended Citation
Youngs, Curtis R., "Cryopreservation of Preimplantation Embryos of Cattle, Sheep, and Goats" (2011). Animal Science Publications. 372.
https://lib.dr.iastate.edu/ans_pubs/372
Comments
This article is published as Youngs, Curtis R. "Cryopreservation of preimplantation embryos of cattle, sheep, and goats." Journal of visualized experiments: JoVE 54 (2011). doi:10.3791/2764. Posted with permission.