Document Type : Original Article
Anatomy Department, Isfahan University of Medical Sciences, Isfahan, Iran
Faculty of Basic Science, Islamic Azad University, Marvdasht Branch, Marvdasht, Iran
Reproduction and Development Department, Royan Institute for Animal Biotechnology, ACECR, Isfahan, Iran
Objective: This study introduced a simple method for bovine blastocyst vitrification.
Materials and Methods: Bovine blastocysts were produced in vitro by means of a whole co-culture system with vero cells. The blastocysts were randomly divided 1:3 into either vitrification (100 blastocysts) or control (43 blastocysts) groups. For vitrification,expanded - blastocysts were incubated first in equilibration medium for 8 minutes and then in the vitrification solution for 1 minute. The blastocysts were then loaded in the tip of a handmade cryotip for immediate - deep freezing in liquid nitrogen. Frozen embryos were then warmed by directly immersing the tips in sequential warming solutions . warmed embryos were cultured for a further period of 48 hours when the ratios of re-expansion, hatching and degeneration were compared with the control group.
Results: After warming, in the vitrified and control groups the ratios of re-expansion were 78.5% ± 0.067 and 81.6% ± 0.072, the ratios of hatching were 43.7% ± 0.083 and 49.8% ± 0.089 and the ratios of degeneration were 36% ± 0.082 and 22.3% ± 0.087, respectively, which were not significantly different between the two groups.
Conclusion: Post - warming survival of the vitrified and non - vitrified embryos were not significantly different, handmade cryotips can be used as an efficient and feasible device for bovine blastocysts vitrification.