Post-rewarming Developmental Competence of in vitro Produced Buffalo (Bubalis Bubalis) Embryos Vitrified Using the Solid Surface Technique.

BACKGROUND Vitrification is an ultra-rapid freezing technique for germplasm preservation under high salt concentration with very short exposure time. OBJECTIVE To assess the post-thawed developmental potential of in vitro-produced buffalo embryos vitrified by solid surface technique using different concentrations of cryoprotectants. MATERIALS AND METHODS The slaughterhouse derived oocytes were in vitro matured and fertilized with epididymal sperm. IVF embryos at the morula stage were vitrified under two protocols; (i) Protocol-1: ethylene glycol (35%) (ii) Protocol-2: ethylene glycol (15%) and dimethyl sulfoxide (15%). The vitrified-thawed embryos were in vitro cultured up to the blastocyst stage. RESULTS Post-thawed development of embryos vitrified under Protocol-1 was significantly higher in terms of compact morula formation as compared to Protocol-2. However, blastocyst developmental rates were not significantly different between the two protocols. The developmental rates of the non-vitrified control were significantly higher than embryos vitrified by either protocols. CONCLUSION The process of cryopreservation, under both protocols, significantly affected the developmental potential of pre-implant embryos as compared to fresh embryos. Hence the nature and concentrations of cryoprotectants needs to be optimized for efficient, viable embryonic development.