The optimal equilibration time for mouse embryos frozen by vitrification with trehalose.
To determine the best equilibration time in the cryoprotectant before rapid cooling, 8-cell mouse embryos were exposed to a vitrification solution containing ethylene glycol, Ficoll and trehalose in modified phosphate-buffered saline at 5 degrees C for varying periods of time. They were frozen using an ultra rapid freezing method, thawed in a 20 degrees C water bath and cultured for 24 h with 5-bromo-2-deoxyuridine. Embryo development and the number of sister chromatid exchanges, a sensitive indicator of genetic damage, were observed. The results demonstrated that embryo development after freezing and thawing was similar among the groups exposed for periods of 5-40 min. However, the number of sister chromatid exchanges was significantly smaller in the group exposed for 5 min, indicating that this was the safest equilibration time in the vitrification solution.
Ishida
G M
GM
Department of Obstetrics and Gynecology, Yamagata University School of Medicine, Iida-Nishi, Japan.
Saito
H
H
Ohta
N
N
Takahashi
T
T
Ito
M M
MM
Saito
T
T
Nakahara
K
K
Hiroi
M
M
D000818:Animals; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000633:toxicity; D004249:DNA Damage; D004622:Embryo, Mammalian / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D005260:Female; D008297:Male; D051379:Mice; D012854:Sister Chromatid Exchange; D012996:Solutions; D013997:Time Factors; D014199:Trehalose / Q000633:toxicity
D003451:Cryoprotective Agents; D012996:Solutions; D014199:Trehalose