Cryobiological effects of cryoprotectants on morphology of cumulus oocyte complexes (COCs) of sheep using vitrification

The aim of this study was to investigate the effect of different cryoprotectants like glycerol and DMSO individually and in combination of both on morphology of sheep oocyte using vitrification. The vitrification of sheep oocyte was performed using 40% glycerol and 40% DMSO individually and in combination of 20% glycerol + 20% DMSO. It was found that combination of cryoprotectants proved more efficient than using 40% glycerol or 40% DMSO alone. The morphological damages were found less (8%) using combination of 20% glycerol+20% DMSO as compared with using 40% Glycerol or 40% DMSO alone which was 16% and 15% respectively. Glycerol and DMSO when used alone found to induce adverse effect on the morphology of sheep oocyte. However combination of 20% glycerol + 20% DMSO found better to maintain the integrity and internal structure of sheep oocyte by vitrification.