Ultrarapid Freezing of Mouse Two-Celi Embryos in Conventional Straws and on Aluminum Foils

Main Article Content

Teraporn Vutyavanich
Suchada Mongkolchaipak
Waraporn Piromlertamorn

Abstract

Objective To compare the success rates of ultrarapid freezing of mouse two-cell embryos in straws and on aluminum foils.

Design               Laboratory experimental study.

Setting               Assisted conception laboratory, Chiang Mai University.

Subjects            Two-cell embryos from superovulated and mated ICR mice.

Intervention      Embryos were divided into 3 groups: 177 were not frozen (control), 172 were

frozen on aluminum foils and 171 in straws. Freezing was done by exposing embryos to 3M DMSO/0.25M sucrose for 2.5 minutes and plunged into liquid nitrogen. Thawing was done by dipping foils into 0.25M sucrose at 37°C or straws into 37°C water-bath and expelled embryos into 0.25M sucrose. Control and frozen/thawed embryos were cultured in G1.2 medium for 24 hours and in G2.2 medium for another 48 hours.

Main Outcome Measures Survival immediately after freezing/thawing, proportions of survived embryos that underwent further cleavage and those that developed into blastocysts and hatching blastocysts.

Results              Embryos frozen on aluminum foils had a significantly higher survival rate than

those frozen in straws (94.8% versus 88.9%; p=.047). They underwent further cleavage at a higher rate (135/163; 82.8% versus 91/152; 59.9%, p<.001). Proportions of embryos that became blastocysts (105/163; 64.4% versus 64/152; 42.1%) and hatching blastocysts (48/163; 29.4% versus 14/152; 9.2%) were also significantly higher (p<.001). Controls had higher (p<.05) cleavage rate (161/177; 91%), and higher (p<.001) rates of blastocyst (136/177; 91%) and hatching blastocyst formation (99/177; 55.9%) than embryos that underwent freezing/thawing.

Conclusion Ultrarapid freezing on aluminum foils gave better results than ultrarapid freezing in conventional straws.

Article Details

How to Cite
(1)
Vutyavanich, T.; Mongkolchaipak, S.; Piromlertamorn, W. Ultrarapid Freezing of Mouse Two-Celi Embryos in Conventional Straws and on Aluminum Foils. Thai J Obstet Gynaecol 2017, 15, 185-190.
Section
Original Article