Vitrification of bovine ovarian tissue by the solid-surface vitrification method

Exposure time and addition of sucrose to the vitrification medium as well as the solid-surface vitrification (SSV) on the morphology of bovine preantral follicles were evaluated. Ovarian tissue was exposed for 1, 5, or 10 min to 4.0 M ethylene glycol with or without the addition of 0.5 M sucrose. Subsequently, the tissue was washed out from cryoprotectants or vitrified by the SSV method. Independently of the presence of sucrose, exposure to vitrification solution for 10 min did reduce the percentages of normal follicles when compared with control. However, the highest rates of normal follicles were attained when tissue was previously exposed to the vitrification solution, with sucrose added or not, for 10 min. Although the SSV is a promising procedure to be applied in ovarian tissue, an optimal vitrification solution for bovine ovarian tissue needs to be developed.