Objective:To observe the effects of vitrification pretreated with cytochalasin B on the potency of thawed mouse oocytes.Methods:Mouse mature oocytes were cultured with cytochalasin B of different concentrations of 0(control)

5

10

20

40 μg/ml

respectively

and then vitrificated.After the oocytes were thawed

we observed the oocyte recovery rate

fertilization rate

and embryo formation rate of 6～8 cell.Results:CB groups of 20

40 μg/ml had higher recovery rate than the control groups

with significant difference(P<0.01);the CB group of 20 μg/ml was of no significant difference with the 40 μg/ml group(88.7% vs 87.6%

P=0.767).The fertilization rate and embryo formation rate of 6～8 cell in any group was of no significant difference(P>0.05).Conclusion:The concentrations of 20

40 μg/ml can be used to improve the recovery rate of mouse mature oocytes.