: Fahrig, R.

Abstract
Several methods exist for detecting the genotoxicity and especially the mutagenicity of physical or chemical agents. For the extrapolation of experimental results to man, in vivo results are more relevant than in vitro ones. Risk estimations for man gained from in vivo data are more reliable than those from in vitro data. The spot test is the best validated method for detection of genotoxic alterations, namely gene mutations and recombinations, in somatic cells of mice. (...) Like other mutagenicity tests, the spot test not only serves for detecting mutagenic effects but also for detecting carcinogenic potential. An important feature of the spot test is its ability to detect recombinations which can unmask carcinogen-induced mutations, as well as being able to detect gene mutations which play a role during initiation. In recent years, the spot test has gained importance in detecting recombinogenic effects, which are regarded as important in tumour promotion.