Simultaneous determination of cellular mutagenesis and transformation by chemical carcinogens in Fischer rat embryo cells.

Thirteen chemicals, eight carcinogenic and five closely related noncarcinogenic analogues, were tested to establish the validity of a simultaneous procedure for the in vitro assay of potential carcinogens and mutagens. The assay utilizes Fischer rat embryo (FRE) cells infected with Rauscher leukemia virus and simultaneously measures the induction of cellular transformation (growth in soft agar) and mutagenesis (ouabain resistance) by chemicals. An activation procedure for the metabolic conversion of the procarcinogens and promutagens to biologically active forms is described. All chemicals that produced transformation in the FRE system also induced a significant increase in ouabain resistance. The significance and the potential uses of this assay are discussed.