Cryopreservation of mouse and bovine embryos using methanol as cryoprotectant.

Abstract

Mouse embryos were collccted from superovulated animals on the fourth day after IICG injection. They were put directly into a solution of 3 M methanol in PBSS at room temperature during ten minutes. Thawing was carried out in a waterbath at 37 ºC during 20seconds. Embryos were placed directly into PBSS washed twice and put into culture using medium T6 supplemented with 10% fetal calf serum at 37 °C in a humid atmosphere of 5% CO2 , 5% 02 and 90% N2 . Bovine embryos were cultured under the same conditions, only using PBS supplemented with 20% fetal calf serum as culture medium. Of the 104 frozen mouse embryos, 48,2% continued developing in culture after thawing. None of the eight bovine embryos that were thawed and transferred directly to recipients resulted in pregnancy and none of the twelve bovine embryos that were thawed and put into culture continued to develop.