흰쥐배의 동결보존에 관한 연구 = Study on the Freezing of Rat Embryos

다국어 초록 (Multilingual Abstract)

This experiment was carried out to provide the basic data for developing new techniques of freeze preservation of embryos. Effects of developmental stage of embryos, concentration of DMSO, seeding point, preliminary freezing temperature, freezing rate and thawing temperature on the survival of rat embryos were investigated. The results obtained were as follows: 1. The survival rate of embryos frozen at the developmental stages of 1-cell embryos, 2-cell embryos, 4-cell embryos, 8-cell embryos and morula was 42.1%, 64.7%, 70.0%, 83.3% and 68.4%, respectively. 2. When the concentration of DMSO was adjusted to 0.25 M, 0.5M, 1.0M, 1.5M and 2.0M, the survival rate of frozen 8-cell embryos was 0.0 %, 47.3 %, 88.8 %, 70.6 % and58.8 % respectively. 3. When the seeding point was fixed to -2℃, -4℃, -6℃, -8℃ and -10℃, the survival rate of frozen 8-cell embryos was 42.1%, 75.0%, 84.2%, 77.8% and 15%, respectively. 4. The survival rate of 8-cell embryos frozen at the preliminary freezing temperature of -30℃, -40℃, -50℃, -60℃ and -70℃ was 16.6%, 35.0%, 61.0%, 68.4% and 83.3%, respectively. 5. When the freezing rate was adjusted from -40℃ through LN₂ gas to LN₂(-40℃→LN₂ gas→LN₂), -50℃→LN₂gas→ LN₂, -79℃→LN₂ gas→LN₂,-40℃→-79℃→LN₂gas→LN₂ and -50℃→ -79℃→LN₂ gas→LN₂ the survival rate of frozen 8-cell embryos was 75.0%, 82.3%, 72.2%, 89.4% and 77.8%, respectively. 6. When the embryos were thawed under different conditions such as soaking in warm(40℃) water, leaving at room temperature, soaking in ice water, soaking in cold(-20C) water followed by warm(40℃) water and soaking cold(-70℃) water followed by warm(40℃) water, the survival rate of frozen 8-cell embryos was 73.7%, 80.0%, 55.5%, 85.0% and 75.0%, respectively.