Viability of Cows’ Oocytes Derived from Decondensed Ovaries

Abstract

Viability of oocytes extracted from decondensed ovaries of cows stored at -18, -80, -196^oC is studied. Ovaries were frozen with no standard freezers. The method effectiveness was estimated by the cumuli layers safety, membrane integrity, oocytes’ ooplasm condition and the level of cleavage. It is determined that cryopreservation with no cryoprotector, storage at -18^oC for up to 6 months, decindensing in 0.3M of sucrose at +20 ^oC let us get 15,6% of cleaving cells. Cryopreservation in 1,4M glycerine in two steps, storage at -80^oC for up to 20 years, decondensing using 0.3M of sucrose promotes viability and fertilization rate of 18,2% of cells. Absence of cryophylactic at freezing preparation, storage at -80^oC and decondensing with 0.3M of sucrose let us get 23,8% of cleaving cells and 80% of them are deformed. The perfect regime of cryopreservation and storage in liquid nitrogen is the method of vitrification of ovaries samples using 1,5M of propanediol.