Hasler J F, Hurtgen P J, Jin Z Q, Stokes J E
Em Tran, Inc. Elizabethtown, PA 17022, USA.
Theriogenology. 1997 Sep;48(4):563-79. doi: 10.1016/s0093-691x(97)00274-4.
Survival of IVF-derived bovine embryos of different ages and stages of development, produced in 2 different co-culture systems and frozen in 2 different cryoprotectants, was investigated. In vitro-derived bovine embryos (n = 5,525) were utilized to study survival following exposure to cryoprotectants and after freezing. Survival of the frozen embryos was based on blastocyst re-expansion 24 h and hatching 72 h after thawing. There was no difference in survival when embryos were exposed to either glycerol (Gly) or ethylene glycol (EG) for 10 or 40 min with the cryoprotectant diluted with or without freezing. In 2 of 3 experiments in which a comparison was possible, more blastocysts frozen in 1.4 M glycerol than in 1.5 M ethylene glycol survived. Addition of 0.25 M sucrose to 1.5 M ethylene glycol in the freezing solution did not improve embryo survival. More blastocysts frozen on Day 7 of in vitro culture survived than those frozen on Day 6 or Day 8. On Days 6, 7 and 8, embryos in the most advanced stage of development survived better than those at less advanced stages. Post-thaw survival did not differ for embryos produced in co-culture with Buffalo Rat Liver (BRL) cells with either Menezo B2 Medium or Tissue Culture Medium 199 and frozen in 1.4 M glycerol.
研究了在两种不同共培养系统中产生并在两种不同冷冻保护剂中冷冻的不同年龄和发育阶段的体外受精牛胚胎的存活率。利用体外产生的牛胚胎（n = 5525）研究暴露于冷冻保护剂后以及冷冻后的存活率。冷冻胚胎的存活率基于解冻后24小时的囊胚再扩张和72小时的孵化情况。当胚胎在冷冻保护剂稀释或不稀释且不冷冻的情况下，暴露于甘油（Gly）或乙二醇（EG）10分钟或40分钟时，存活率没有差异。在3个可进行比较的实验中的2个实验中，冷冻在1.4 M甘油中的囊胚比冷冻在1.5 M乙二醇中的存活更多。在冷冻溶液中向1.5 M乙二醇中添加0.25 M蔗糖并不能提高胚胎存活率。体外培养第7天冷冻的囊胚比第6天或第8天冷冻的存活更多。在第6、7和8天，发育最成熟阶段的胚胎比发育较不成熟阶段的胚胎存活更好。与水牛大鼠肝（BRL）细胞在Menezo B2培养基或组织培养基199中共培养并冷冻在1.4 M甘油中的胚胎，解冻后的存活率没有差异。
