ABSTRACT
INTRODUCTION Genotoxicity testing of chemicalswas developedduring the 1950s and 1960s andmuch attention was given during this period to the development of appropriate test models for the detection of germ line mutagens that can induce heritable mutations. During the 1970s, the development of the so-called “Ames test,” a bacterial gene mutation test, initiated a new understanding of the relevance of mutagens for humans. Early testing of hundreds of chemicals demonstrated a strong correlation of mutagenic activity in Salmonella with carcinogenicity in rodents (1,2), and hence, the primary purpose in mutagenicity testing changed to screening for carcinogens. However, it was already recognized at that time that a wider range of genetic alterations than those detectable in a bacterial gene mutation test may be involved in carcinogenesis, in particular effects leading to chromosomal damage. Thus, a battery approach comprising of tests that detect both gene mutation and chromosomal damage was recommended. This initial concept still underlies the testing batteries currently in use.
