title: Effect of rapid addition and dilution of dimethyl sulfoxide and 37 degrees C equilibration on viability of rabbit morulae thawed rapidly.
abstract: The aim of the present study was to examine the effects of various conditions of addition and dilution of dimethyl sulfoxide (Me2SO) and 37 degrees C equilibration, and also the effects of freezing in the solution which was prepared in advance and stored in plastic straws at -20 degrees C on the viability of rabbit morulae thawed rapidly. The embryos were cooled from room temperature to -30 degrees C at 1 degree C/min in the presence of 1.5 M Me2SO using a programmable liquid nitrogen vapor freezing machine with an automatic seeding device, then cooled rapidly, and stored in liquid nitrogen. The frozen straws were thawed rapidly (greater than 1000 degrees C/min). When Me2SO was added in a single step, equilibrated with embryos at 37 degrees C for 15 min and diluted out in a single step, a very high survival was obtained: transferable/recovered, 90%: developed/recovered, 96%. When embryos were pipetted into 1.5 M Me2SO that was prepared in advance, stocked in straws at -20 degrees C, and cooled, the proportions of transferable and developed embryos were equivalent to those of embryos frozen in the solution that was prepared immediately before use.
mesh_terms: D000818:Animals; D002470:Cell Survival; D002970:Cleavage Stage, Ovum / Q000187:drug effects*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D005260:Female; D005615:Freezing; D009028:Morula / Q000187:drug effects*; D011247:Pregnancy; D011309:Preservation, Biological / Q000379:methods*; D011817:Rabbits / Q000196:embryology; D013696:Temperature
chemical_list: D003451:Cryoprotective Agents; D004121:Dimethyl Sulfoxide