Ascites tumor fluid and bovine serum albumin as supplements in presomite mouse embryo cultures.

The growth of presomite mouse embryos in culture was studied using mouse Ehrlich ascites tumor fluid and bovine serum albumin as supplements to the tissue culture medium. The best development was observed with a mixture of 10-20% ascites fluid and 2% bovine serum albumin. During 48 h of culture under these conditions, embryos grew from egg cylinders to complex structures with neural folds and other organ rudiments. Most embryos had beating hearts, numerous pigmented red blood cells, and a fused chorioallantoic placenta. The results suggest that factors in ascites fluid support differentiation and growth of mouse embryos. Addition of bovine serum albumin was also beneficial for development. Differential sister chromatid staining of cultured embryos showed that ascites fluid increased the rate of cell proliferation as compared with medium containing bovine serum albumin alone, or bovine serum albumin and fetal calf serum. These results with abundant and readily available supplements may facilitate certain studies of mouse embryo development.