Effect of various sera on cultured rodent embryonic shields.

The modified organ culture of rodent embryonic shields, developed in our laboratory, has been shown to provide favorable conditions for the differentiation of the main tissues in teratoma-like explants. The purpose of the experiment was to discover whether tissue differentiation is modified by different sorts of sera used in the liquid medium. Rat explants showed an increase of the incidence of cartilage when cultured in at least 20% homologous serum in comparison with human and fetal bovine sera. Mouse explants did not grow in mouse serum, whereas rat serum stimulated the development of endoderm-like epithelium, and fetal bovine serum brought about more neural tissue.