Landa V
Folia Biol (Praha). 1982;28(4):266-73.
Mouse blastocysts frozen slowly (0.3-0.5 degrees C min-1) to -25 degrees C and transferred to -196 degrees C survive long-term storage to the extent comparable to unfrozen blastocysts. After thawing at 450 and 650 degrees C min-1, 91 and 93% blastocysts, respectively, continued normal development under in vitro conditions. The length of equilibration at -25 degrees C before transfer to -196 degrees C had no marked effect on survival of blastocysts. It has been shown that blastocysts stored at -196 degrees C may be transferred into recipients immediately after thawing. The prerequisite of a normal development was the transfer into pseudopregnant females on day 2 of pseudo-pregnancy; 60.3% foetuses were found 14-15 days after transfer. Transfers of thawed blastocysts into pseudopregnant females on day 3 or day 4 of pseudopregnancy failed (3.9 and 0% foetuses, respectively). After transfer of unfrozen blastocysts into pseudopregnant females on day 3 of pseudopregnancy 58.7% foetuses were found. Transfers of unfrozen blastocysts into pseudopregnant females on day 2 and day 4 of pseudopregnancy were less effective (6.4 and 27.3% foetuses, respectively).
小鼠囊胚以0.3 - 0.5℃/分钟的速度缓慢冷冻至-25℃，然后转移至-196℃，长期保存后的存活率与未冷冻的囊胚相当。在450℃/分钟和650℃/分钟的速度解冻后，分别有91%和93%的囊胚在体外条件下继续正常发育。在转移至-196℃之前，在-25℃下平衡的时间对囊胚的存活率没有显著影响。研究表明，储存在-196℃的囊胚解冻后可立即移植到受体体内。正常发育的前提是在假孕第2天移植到假孕母鼠体内；移植后14 - 15天发现60.3%的胎儿。在假孕第3天或第4天将解冻的囊胚移植到假孕母鼠体内失败（分别为3.9%和0%的胎儿）。在假孕第3天将未冷冻的囊胚移植到假孕母鼠体内后，发现58.7%的胎儿。在假孕第2天和第4天将未冷冻的囊胚移植到假孕母鼠体内效果较差（分别为6.4%和27.3%的胎儿）。
