Developmental Toxicity Using the Rat Whole Embryo Culture

In vivo and in vitro experiments have been used to investigate the effect of drugs, chemical agents, growth factors, vitamins, etc., on embryonic development. Alternative tests have been developed to determine whether drugs or other compounds have toxic or teratogenic effects on a particular organ or tissue. The rat whole embryo culture method is useful for studying the mechanism of normal embryo development. The explanted rat conceptuses grow in the culture environment at the same rate as in utero development. Furthermore, the considerable advantage of explanting rat embryos is that it allows direct observation of embryogenesis. The rat whole embryo culture is run by explanting rat embryos on gestation day 9.5 for rats. The conceptuses are then cultured on a rotating platform in a mixture of culture medium with appropriate gassing for 48 hours. The maternal serum is used as the culture medium, and chemicals or other agents to be evaluated separately are added to this medium. At the end of the culture period, growth and development of the embryos are evaluated morphologically.