Freezing IVF Bovine Embryos by One-step Dilution of Cryoprotectants

Dilution of cryoprotectants for freezing of IVF bovine embryos was investigated in this study. Day 7 blastocysts were frozen in 1.4M, 1.0M or 0.7M glycerol (G) using the conventional freezing procedure. After thawing of embryos, glycerol was removed by one-step dilution in 0.25M or 0.5M sucrose (S). When they were frozen in 1.0MG and diluted in 0.5MS significantly more embryos hatched (84.35%) in comparison with them frozen in 1.4MG and diluted in 0.5M (66.67%) or o.25MS(71.43%), and frozen in 0.7MG and diluted in 0.5MS(73.98%). The hatching rate of embryos frozen in 1.0MG (79.65%) was significantly higher (p0.05) than that frozen in 1.4MG(69.48%). This result indicates that the concentration of glycerol significantly influence the survival rate of bovine IVF embryos after frozen-thawed. Appropriate concentration of glycerol for embryo freezing and sucrose for glycerol removed are 1.0M and 0.5M, respectively.