Optimized Method for Bovine Blastocyst Vitrification Using a Simple Hand-Made Cryotip



Asgari V¹ ; Forouzanfar M² ; Hosseini SM³ ; Hajian M³ ; Moulavi F³ ; Abedi P³ ; Hosseini L³ ; Sadeghi H¹ ; Bahramian H¹ ; Esfahani MHN³
Source: Yakhteh Published:2009

Abstract

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.