In vitro fertilization of mouse and hamster eggs after freezing and thawing

Abstract
Mouse eggs (12–14%) and hamster eggs (87–94%) appear normal upon thawing after having been stored for 30 min to 25 h at −70°C and −196°C. While 89–98% of the normal appearing hamster eggs are capable of fertilization in vitro, only 4–13% of the mouse eggs can be fertilized. The ability of fertilized eggs to develop in culture and their viability upon transfer to pseudopregnant recipients is under investigation.