%0 Comparative Study %T Comparison of common gene mutation tests in mammalian cells in culture: a position paper of the GUM Commission for the Development of Guidelines for Genotoxicity Testing. %A Glatt H %J Mutat Res %V 313 %N 1 %D Aug 1994 %M 7519313 %F 3.151 %R 10.1016/0165-1161(94)90028-0 %X In gene mutation tests a decision concerning mutations is made on the basis of hereditary functional changes. In terms of the large amount of data available, the most suitable tests for routine testing in mammalian cells in culture are the tests for acquisition of 6-thioguanine resistance in Chinese hamster cells (V79 and CHO) and for acquisition of alpha,alpha,alpha-trifluorothymidine resistance in the mouse lymphoma line L5178Y TK+/- 3.7.2C. The molecular bases, peculiarities, advantages and disadvantages of these systems will be presented. Which system is to be preferred in any particular case depends among other things on the purpose of the study and the extent to which a technically competent performance of these comparatively exacting tests can be guaranteed.