An in vitro test for teratogens using cultures of rat embryo cells

The embryo, during its phase of organogenesis, may be uniquely sensitive to toxic insult from certain drugs and other xenobiotics. Chemicals that cause irreversible abnormalities of structure and function are defined as teratogens. The mechanisms by which teratogens cause abormalities of development must be considered before designing in vitro tests for teratogens so that methods which have an inbuilt tendency to false negative or positive classification may be avoided. Thus a test which measures inhibition of cell adhesion alone should not (and does not) detect teratogens such as 5 fluorouracil or actinomycin D which are specific inhibitors of the cell cycle (Braun et al, 1979).