Paper published today on AMES test study design for nitrosamines, including showing NMEA as Ames positive.
A fantastic paper! A must read…
The current study confirms the mutagenicity of alkylnitrosamines can be readily detected in the bacterial reverse mutation test (Ames test). Using advanced data analytics and modelling we show the assay parameters most sensitive for this class of compound including the pre-incubation method (with a 30-min incubation period) compared with plate-incorporation. Either water or methanol was suitable as vehicles, and hamster-induced liver S9 was the superior exogenous metabolic system, although rat liver S9 also elicited a positive response, albeit with less potency.
Since there are examples of nitrosamines which are Ames test positive with rat liver S9 and negative with hamster liver S9 , we recommend both systems be used in parallel at the present time. S. typhimurium TA1535 and TA100 and E. coli WP2uvrA (pKM101), were the most sensitive bacterial strains, and these strains should be included as part of the 5-strain Ames test when evaluating the mutagenicity of nitrosamines