Aneuploidy induced by nocodazole or ethyl acetate is suppressed by dimethyl sulfoxide.

Nocodazole and ethyl acetate have previously been shown to be potent inducers of aneuploidy in Saccharomyces cerevisiae. The elevation in aneuploidy frequency induced by high doses of these compounds was reduced in a dose-response manner in the presence of increasing concentrations of dimethyl sulfoxide. These results imply that compounds dissolved in dimethyl sulfoxide which either are weak inducers of aneuploidy or are of unknown potency may register as false negatives in routine screening procedures.