In vitro development of postimplantation rat embryos cultured on dialyzed rat serum.

Attempts to culture postimplantation rat embryos on defined media have not been successful although they grow well when cultured on homologous serum. As a first step in the search for factors in serum that support growth and differentiation of such cultured preparations the following experiments were undertaken. Six-somite rat embryos were cultured on whole serum, dialyzed serum, or the buffered salt solution (BSS) used for dialysis. Additional experiments were conducted utilizing BSS supplemented with glucose or dialyzed serum supplemented with glucose, mannose, fructose, or pyruvate. Of the media tested only glucose-supplemented dialyzed serum maintained development at a level comparable to that obtained with whole serum. Further preliminary studies with combined supplementation and metabolic poisoning suggested that anaerobic glycolysis is essential for the in-vitro growth and differentiation of these preparations.