The Effect of Equilibration Temperature and Exposure Time on the Ultrarapid Freezing of 1-cell Mouse Zygote / 대한불임학회지

ABSTRACT

The present study was to assess the effect of ultrarapid freezing on the development of 1-cell mouse zygote using cryoprotectants, DMSO (dimethyl sulfoxide) or PROH (1,2-propanediol). We investigated the effect of the type and concentration of cryoprotectant, and of the temperature and time of prefreezing equilibration on their capacity to develop to the blastocyst stage in vitro. The concenration, the equilibration temperature, and the exposure time seemed to serve as an important factor in ultrarapid freezing of 1-cell mouse zygotes. In addition to the exposure time and the concentration of cryoprotectant appeared to play a key role in the development of the embryo. In general, the development of the embryo was more effective at 3degrees C than 23degrees C and 4.5 M than 3 M for 3 to 5 minutes. At 23degrees C the development of the embryo was stimulated by DMSO while at 3degrees C it was stimulated by PROH. Thus it has been suggested that there exists a correlation between the concentration of cryoprotectants and exposure time in the development of the embryo. In conclusion, we found that for ultrarapid freezing of mouse 1-cell embryos in DMSO, or PROH-based solution, viability shown optimum depending on the cryoprotectant, the concentration of the cryoprotectant and on the temperature and the duration of equilibration.