Comparison of In Vitro Development of Mouse Early Blastocysts according to Vitrification and Conventional Slow Freezing Procedures

Oh, D S; Lee, K S

Abstract

This study was undertaken to investigate the rapid and optimum freezing procedure that can maintain a high survival rate after post-thaw blastocysts, determining the effects of vitrification and conventional slow freezing procedures on in vitro post-thaw recovery and developmental rates of mouse early blastocysts, respectively. The results were as follows: 1. The rate of in vitro development from zygote(in vivo fertilization) to mouse early blastocysts before cryopreservation was 78.4%. 2. The post-thaw recovery rates after vitrification and conventional slow freezing precedures for mouse early blastocysts were 86.7% and 90.5%, respectively. 3. The post-thaw developmental rates to hatched blastocyst after vitrification and conventional slow freezing procedures were 43.5% and 54.7%, respectively. These results showed that the post-thaw recovery rates and the post-thaw developmental rates to hatched blastocyst after vitrification and conventional slow freezing procedures for mouse early blastocyst were not significantly different. Thus, it is suggested that the vitrification procedure is useful in cryopreservation of mouse early blastocysts without controlled-rate freezing equipment, and that proposed vitrification procedure provides the possibility for its use in freezing human blastocyst.