小鼠胚胎的玻璃化冷冻研究

Vitrification Study on Mouse Embryo

用不同冷冻载体(玻璃管、塑料管和0.25 mL细管)及不同冷冻方法(程序化冷冻和玻璃化冷冻)对小鼠3.5 d^4 d桑椹胚和囊胚进行冷冻保存,并与不做任何冷冻保存处理直接培养进行对比。结果表明,使用玻璃管、塑料管和0.25 mL细管作为胚胎的承载材料进行玻璃化冷冻,效果差异不显著;采用程序化冷冻与OPS玻璃化冷冻法,对小鼠胚胎进行冷冻保存可以取得较好的结果。从而得出,用不同材质的冷冻载体进行玻璃化冷冻,可以获得与程序化冷冻相同的良好效果。

In the present study, mouse embryos （3.5-4 days） collected from superovulated mice were frozen by open pulled straw （OPS） vitrification and conventionally frozen before in vitro culture. The objective was to assess embryo survival rate and process of embryo handling during commercial embryo transfer （ET） using the conventional freezing method as a comparison. The results as following： （1） The morphologically normal rates of thawed morulae and blastocysts with glass straw, open pulled straw and 0.25ml straw as a carrier were 95.23%, 89.66% and 97. 01%, respectively, for morulae; 92.00%, 86.84% and 75.47% for blastocysts. Developing rates of thawed morulae were 87.57%, 86.40% and 75.51%, respectively; during the vitrification of thawed blastocysts, developing rates reached 85.83, 77. 14, 68.89 % with glass OPS, plastic OPS and 0.25 mL straw. （2） Morphologically normal rates of embryos vitrified or conventionally frozen were 97.78% vs. 94. 64% at the morula stage, and 95.12% vs. 100%. The developing rates of embryos vitrified or conventionally frozen were 95.45% vs. 88.94% at the morulae stage, and 86.16% vs. 83.33% at the blastocysts stage, respectively, No significant difference was found at the blastocysts stage between vitrified or conventionally frozen （P 〉0.05）, although significant difference was found at the morulae stage between vitrified or conventionally frozen （P 〈0.05）. The study demonstrated the same survival rates for vitrified and conventionally cryopreserved embryos of morula and blastocyst stages during in vitro embryo culture. OPS vitrification is an effective and rapid method of cryopreservation of mouse embryos.