title: Cryoprotection of day-4 mouse embryos by methanol.
abstract: Methanol was examined as a cryoprotective additive that permits the direct transfer of frozen--thawed Day-4 mouse embryos to foster mothers without dilution of the cryoprotectant. Methanol permeated the embryos rapidly, was not toxic and exerted a cryoprotective action. The highest level of survival (50%) of embryos in vitro was observed after equilibration in Medium PB1 containing 3.0 M-methanol, slow cooling (0.5 degrees C/min) to a temperature between -30 and -40 degrees C, rapid cooling (800 degrees C/min) and storage in liquid nitrogen (-196 degrees C), rapid warming (800 degrees C/min), and rapid dilution. A high rate of development in vivo to late-stage fetuses (up to 81%) was observed when cryopreserved embryos were transferred to pseudopregnant recipients immediately after thawing.
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology*; D002970:Cleavage Stage, Ovum / Q000502:physiology*; D003451:Cryoprotective Agents; D004624:Embryo Transfer / Q000379:methods; D005615:Freezing; D000432:Methanol; D051379:Mice; D008815:Mice, Inbred Strains; D008858:Microscopy, Phase-Contrast; D009028:Morula / Q000166:cytology / Q000502:physiology*; D009995:Osmosis; D014021:Tissue Preservation; D014022:Tissue Survival
chemical_list: D003451:Cryoprotective Agents; D000432:Methanol