Survival of mouse embryos after freezing in medium containing dimethylsulphoxide and yolk extract

The ability of the cryoprotective solution containing dimethylsulphoxide in combination with yolk extract (DYG 550) to protect mouse embryos at ultra low temperatures is reported. Of the embryos of 46.1% frozen to -196 C at various rates formed blastocysts in vitro compared to 41.2% and 23.2% survivals protected by 1M dimethylsulphoxide and 1M glycerol.