Effects of different cryoprouectants and cryopreservation protocols on the development of mouse 2-cell embryos

Objective To evaluate the effects of different cryoprotectants and different cryopreservation protocols on the development of mouse 2-cell embryos. Methods Mouse 2-cell embryos were cryopreserved using propylene glycol (PROH), ethylene glycol (EG), demethyl-sulphoxide (DMSO) or glycerol (G) as cryoprotectants with slow-freezing or Vit-Master vitrification protocol. After thawing, the survival rate, blastocyst formation rate and blastocyst hatching rate of the embryos were compared with each other. Results When the mouse 2-cell embryos were cryopreserved by the slow-freezing,the survival rate, the blastocyst formation rate and the blastocyst hatching rate of the embryos with PROH were significantly higher than those with DMSO and G (P0.05), but not significantly different among those with DMSO, G or EG (P0.05). When the mouse 2-cell embryos were cryopreserved by Vit-Master vitrification, the survival rate, the blastocyst formation rate and the blastocyst hatching rate of the embryos with EG were significantly higher than those with PROH, DMSO or G (P 0.05). However, there were no significant differences among those with PROH, DMSO or G (P0.05). Conclusion PROH is an optimal cryoprotectant for the cryopreservation of mouse 2-cell embryos when slow-freezing protocol is used. EG is an optimal cryoprotectant for the cryopresevation of mouse 2-cell embryos when Vit-Master vitrification protocol is adopted, which may substitute for slow-freezing protocol that has been commonly used in clinical and laboratory practice.