Effect of different vitrification carriers on the freezing human ovarian tissue

Objective: To compare the effects of different vitrification carriers on the freezing human ovarian tissue,and provide the theoretical and experimental basis in selecting frozen solution.Methods: The human ovarian cortex tissues were cut into the size of 10 mm×1 mm×1 mm,randomly divided into the fresh group(group A),needle immersed vitrification group(group B),solid surface vitrification group(group C) and direct covered vitrification group(group D) according to different vitrification carriers.The fresh group were fixed by 10% formaldehyde,embeded in paraffin,sectioned and stained with hematoxylin and eosin.The other three groups were preserved in liquid nitrogen after freezing for two months,then fixed,sectioned and stained using rapid rewarming protocol.The proportions of normal primordium follicles in group B,C and D were calculated by histological analysis,which was used to analyze the frozen effects.Results: There were 809 primordial follicles in four groups,the proportions of normal primordium follicles in group A,B,C and D were 96.12%,88.14%,80.00% and 81.25%,respectively.The proportions of normal primordium follicles in group B,C and D were lower than that in group A(P< 0.01),but the differences of which between group B,C and D were not statistically significant(P >0.05).Conclusions: Compared with the fresh tissue,the proportions of normal primordium follicles decrease after freezing,but the vitrification freezing can be used to preserve the human ovarian tissue still.