Korean J Fertil Steril.  1998 Apr;25(1):71-76.

Developmental Capacity of Bovine Follicular Oocytes after Ultra-Rapid Freezing by Electron Microscope Grid I. Cryopreservation of Bovine Immature Oocytes

• Kim EY
• Kim NH
• Yi BK
• Yoon SH
• Park SP
• Chung KS
• Lim JH

Abstract

SUMMARY This study was carried out to examine whether the developmental capacity of bovine immature oocytes frozen ultra-rapidly using electron microscope (EM) grids and EFS30 can be obtained. As freezing solution, we used EFS30 which consisted of 30% ethylene glycol, 0.5M sucrose, 18% ficoll and 10% FBS added in D-PBS. As criterion of oocyte viability, the rates of maturation, fertilization and embryonic development were determined. The results obtained in this experiment were summarized as follows: When ultra-rapidly frozen immature oocytes were thawed, 43.2% of them were survived. The rates of maturation (84.1%) and normal 2 pronuclei formation (57.5%) of frozen immature oocytes were not significantly different when compared to those of control (92.5, 65.0%). In addition, the rates of > or =2-cell (65.0%) and blastocyst formation (30.8%) of freezing group were not significantly different when compared to those of control (73.7, 35.7%). These results demonstrate that developmental capacity of frozen-thawed bovine immature oocytes can be successfully obtained when survived from the ultra-rapid freezing method using EM grid and EFS30.

MeSH Terms

Blastocyst
Cryopreservation*
Embryonic Development
Ethylene Glycol
Female
Fertilization
Ficoll
Freezing*
Oocytes*
Pregnancy
Sucrose
Ethylene Glycol
Ficoll
Sucrose