FREEZE-STORAGE OF EARLY EMBRYO OF RAT

摘要

PURPOSE:To enable the freeze-storage of an early embryo of rat in high survival ratio, by freezing a bicellular embryo under a specific cooling condition. CONSTITUTION:An embryo of bicellular stage collected from a mature female rat subjected to superovulation-inducing treatment (administration of pregnant- mare serum gonadotropic hormone and human chorionic gonadotropic hormone) is transplanted to a freeze-storage medium added with fetal calf serum and a freeze-protective agent (e.g. DMSO, propylene glycol, etc.) at normal temperature, equilibrated for about 5-15min, slowly cooled, left at rest at about -7 deg.C for about 10min and subjected to seeding treatment during the above stage. The embryo is cooled at a rate of 0.5-1.0 deg.C/min until the temperature reaches -20--40 deg.C, preferably -30 deg.C, when the embryo is transferred into liquid nitrogen and stored.