BS in Animal Science
Animal Science Department
The objectives of this study were to: (1) determine an optimal cryoprotectant of mice embryos; and (2) determine whether morula or blastocyst stage is ideal for vitrification in both medias. One experiment was performed using two different medias for vitrification with open pulled straws (OPS) with morulae and blastocysts. In the first protocol, we called V, embryos were exposed to 10% ethylene glycol (EG) for 5 minutes, then 40% ethylene glycol and 0.6 M galactose for about 30 seconds, loaded into an OPS, and plunged into liquid nitrogen. In the second protocol, we called VG, embryos were exposed to 7.5% EG + 7.5% dimethyl sulfoxide (DMSO) for 3 minutes, 16.5% EG + 16.5% DMSO and 0.5 M sucrose for about 30 seconds, and loaded and plunged into liquid nitrogen. Cryoprotectants were removed after warming in three steps at 3-minute intervals. All embryos were cultured for 24-48 hours after warming. Survival rates for morulae and blastocysts were similar (P > 0.05) in both media. The overall survival of all embryos, regardless of stage of development, was better for embryos vitrified using the V method rather than the VG method (P < 0.05).