Viability of ovarian tissue after freezing

Abstract

The fertilized egg of the rabbit, obtained from the Fallopian tube, is very sensitive to freezing and thawing, even after treatment with glycerol (Smith 1953). By contrast, the cumulus cells of the follicular granulosa which adhere to the egg after ovulation are much more resistant, and a few survive without any special precautions being taken (Smith 1949). A systematic study of the viability of the cumulus cells cultured after freezing and thawing by various methods (Smith 1953) gave the following results: (1) A majority of the cells survived when suspended in homologous serum, cooled slowly to — 79° C and thawed rapidly at + 40° C. Very few survived rapid freezing. (2) Addition of 15 % glycerol to the suspending medium improved survival after slow cooling but not after rapid cooling. (3) Cells suspended in normal saline failed to survive either slow or rapid cooling. Addition of glycerol promoted some survival after slow cooling. These experiments emphasized the need for slow cooling, already demonstrated with bull spermatozoa, and the superiority of serum over saline as a suspending medium. The addition of glycerol to the medium, though conducive to survival after freezing and thawing, was not as necessary as with spermatozoa.