ABSTRACT
BACKGROUND: Vitrification is commonly used for cryopreservation of gametes. OBJECTIVE: The study aimed at evaluating viability and developmental competence of bovine oocytes vitrified by Rapid-I method. MATERIALS AND METHODS: Oocytes after collection (group 1) and IVM (group 2) were vitrified using medium containing 18% Ficoll, 40% ethylene glycol, 0.3 M sucrose. To evaluate viability, oocytes after warming were stained with fluorescein diacetate and ethidium bromide. In experiment 2, oocytes after IVM and vitrification were activated by 0.5 µM ionomycin in TCM 199 combined with 2 mM 6-DMAP in TCM 199 with 10% fetal bovine serum. RESULTS: Survival rate in group 1 was 58%, and 88% in the control. In group 2, 63% viable oocytes were found, compared to 82% in the control group. After parthenogenetic activation 27.2% morulas were observed. This percentage was lower than in the non-vitrified group (31%). CONCLUSION: Maturity stage of bovine oocytes has no effect on their survival after vitrification.
