Liquid nitrogen vapour freezing of mouse embryos

Publisher Website
Google Scholar
Abstract
Mouse morulae were frozen rapidly to -196.degree. C in the presence of glycerol by a two-step procedure; the embryos were transferred directly from -7.degree. C after seeding into liquid nitrogen vapour at -170 to -180.degree. C and then into liquid nitrogen 10-15 min later. Suitable conditions for the survival of embryos frozen with liquid nitrogen vapour were found to be: 2 M-glycerol, 2 M-propylene glycol, 2 M-ethylene glycol; 5-30 min equilibration time at 0.degree. C; 3-60 min holding time in liquid nitrogen vapour; dilution of glycerol with sucrose out of the frozen-thawed embryos; morula and early blastocyst stage embryos. Relatively high survival rates (69-74%) were obtained after rapid freezing by liquid nitrogen vapour. Morulae frozen in this fashion, cultured and transferred to recipients developed into normal young.