Comparison and Avoidance of Toxicity of Penetrating Cryoprotectants
Figure 4
Avoidance of CPA toxicity and improvement of the cryosurvival.
(A) Post-exposure survival, fertilization, and embryonic development. PROH and DMSO were combined using half (i.e., 0.75 M) of their typical concentrations to bring the total CPA concentration to a cryoprotective level without a significant toxic effect. Subsequently, ovulated mouse oocytes were exposed to a 1.5-M mixture of PROH and DMSO at both RT and 37°C for 15 minutes, and then were evaluated for their post-exposure survival, fertilization, and embryonic development rates. Data shown are mean±SEM. The total number of oocytes (n) used in each group was also shown. There was no significant difference between the groups (p>0.05). (B) Post-thaw survival rates. Ovulated mouse oocytes were loaded with either 0.75 M PROH+0.75 M DMSO or 1.5 M DMSO at RT for 15 minutes, and then subjected a freeze-thaw cycle to evaluate the cryoprotection of the combined 0.75-M concentrations of PROH and DMSO with respect to a commonly used concentration of DMSO alone. Data shown are mean±SEM. The total number of oocytes (n) used in each group was also shown. * denotes significant difference in the cryosurvival (p<0.001).