A Modified Allium Test as a Tool in the Screening of the Genotoxicity of Complex Mixtures

Abstract

A modified protocol for the Allium test with regard to the usually observed microscopic parameters is presented. In three different experiments, Allium root cells were exposed to methyl methanesulfonate (10 and 15 μg/1), nondiluted waste water from a slaughter-house and from a dye-house (the last one without any genotoxic effect). In the proposed scoring method only anaphase and early telophase cells are observed (100 cells per onion), and bridges, fragments, and vagrants are scored and pooled as chromosome aberrations. This method of scoring is compared with the one where metaphase, early anaphase, and normal anaphase cells are observed (100 per onion), and bridges, vagrants, fragments, c-mitoses, and sticky chromosomes are scored and classified separately in these chromosome aberration categories. Using the X2-test it is shown that the proposed modified method of scoring is more sensitive, having higher levels of significance than the more commonly used method. It is recommended to use the modified Allium test as an easy and sensitive screening method of complex mixtures for genotoxicity.