Serum variants causing the formation of double hearts and other abnormalities in explanted rat embryos

Abstract

Rat embryos explanted before organogenesis (⁠ days gestation) were grown in culture in homologous serum. When the serum was prepared from blood centrifuged after clotting, the embryos developed double hearts. In serum prepared from blood centrifuged before clotting had occurred, and in plasma, the embryos developed normal single hearts. The delayed-centrifuged (D.C.) serum also supported less growth of older embryos than the immediately-centrifuged (I.C.) serum. The harmful properties of D.C. serum appeared rapidly in contact with a normal blood clot but did not develop in contact with separated blood cells and fibrin clot. Mixtures of D.C. and I.C. sera gave results intermediate between those from the two sera alone. No significant differences were found between D.C. and I.C. serum in calcium or complement content but both supported better embryonic development after pre-heating.