Establishment of Mouse Oocytes Cryopreservation Program.

Moon, Shin Yong; Kim, Seok Hyun; Jee, Byung Chul; Sung, Ki Cheong; Choi, Sung Mi; Kim, Hee Sun; Oh, Sun Kyung; Suh, Chang Suk; Choi, Young Min; Kim, Jung Gu; Lee, Jin Yong

Obstet Gynecol Sci > Volume 44(8); 2001 > Article

Original Article

Korean Journal of Obstetrics & Gynecology 2001;44(8):1455-1463.
Published online: August 1, 2001

Establishment of Mouse Oocytes Cryopreservation Program.

Shin Yong Moon, Seok Hyun Kim, Byung Chul Jee, Ki Cheong Sung, Sung Mi Choi, Hee Sun Kim, Sun Kyung Oh, Chang Suk Suh, Young Min Choi, Jung Gu Kim, Jin Yong Lee

Department of Obstetrics and Gynecology, College of Medicine, Institute of Reproductive Medicine and Population, Medical Research Center, Seoul National University, Seoul, Korea.

Abstract

OBJECTIVE
To establish the optimal cryopreservation method in mouse oocytes. METHODS: Firstly, mouse immature oocytes were exposed to various cryoprotectants, and then cryoprotectant with the best outcome was selected. Secondly, mouse immature oocytes were cryopreserved by either slow freezing and ultra-rapid thawing or vitrification. Finally, in mouse mature oocytes, the five different protocols were compared in their fertilization and hatching rates. RESULTS: 1) 1.5M 1,2-propanediol (PROH) and 1.5M PROH+0.1M sucrose had a higher rate of survival (73.1%, 81.9%) and in vitro maturation (28.2%, 30.1%). 2) Vitrification using 5.5M ethylene glycol (EG) showed significantly higher rate of survival and in vitro maturation, when compared with slow freezing and ultra-rapid thawing using 1.5M PROH+0.1M sucrose (65.9% vs 50.0%, 40.0% vs 28.2%, respectively). 3) In mouse mature oocytes, vitrification using 5.5M EG showed significantly higher survival rate, however, slow freezing and ultra-rapid thawing using 1.5M DMSO was superior to vitrification in view of fertilization rate. CONCLUSIONS: Vitrification showed better outcomes in mouse immature oocytes, but slow freezing and ultra-rapid thawing using 1.5M DMSO may be beneficial in mature oocytes.

Keywords: Mouse oocytes; Cryopreservation; Slow freezing and ultra-rapid thawing; Vitrification