Study on survival rate and hatching rate of mouse embryos after cryopreservation-thawing by vitrification and program freezing

Objective: To study the effect of cryopreservation-thawing mouse embryos by two methods-program freezing and vitrification, we will apply vitrification into cryopreservation human embryos. Methods: 2-cells mouse embryos were collected after giving 6～8 weeks old mouse COH (controlled ovarian hyperstimulation) and mated with male mouse; randomly allocated 685 2-cell embryos into two groups: program freezing and vitrification, then cryopreservation-thawing and incubating these embryos. The survival rate and hatching rate were compared. Results: The survival rates of vitrification and program freezing were 63.82%(224/351), 62.57% (209/334) respectively (P0.05); The hatching rates of vitrification and program freezing were 34.2% (120/351), 31.74% (106/334) respectively (P0.05). This result indicate that there are no significantly difference in vitrification and program freezing. Conclusion: Vitrification seems to be an effective, easy and rapid method for the cryopreservation of two-cell mouse embryos. So vitrification is the most of all perfect techniques for cryopreservating mouse embryos that can be used to replace classical program freezing.