These studies were carried out to investigate the optimal freezing protocol for 2 cell mouse embryos and to find the probability of quality control with 2-cell embryos frozen.
The embryos showed the best survival by the protocol composed of a freezing solution with the cryoprotectants (1.5M propanediol+0.1M sucrose), and a 2-steop thawing method (room temperature, 20 sec-37℃, 20 sec).
The developmental ability of frozen-thaw 2-cell embryos did not differ from that of fresh 2-cell embryos in m-KRB medium with 0.4% bovine serum albumin. But development of frozen-thaw embryos was depended on the supplements of the medium. In the
albumin-free medium, the developmental rate (rate of blastocysts) was significantly reduced, compared with that in the medium with 0.4% BSA.
Also, when frozen-thaw embryos were cultured in the meduim with human fetal cord serum (HCS), the developmental rate of frozen-thaw embryos was sligtly reduced, compared with that of fresh 2-cell embryos.
Finally, frozen-thaw 2-cell mouse embryos were more sensitive to the toxic agent of disposable-plastic syringe. Therefore, toxicity of medium could be effectively detected by frozen-thaw 2-cell mouse embryos.
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