Introduction. The bacterial reverse gene mutations test (the Ames test) is widely used to assess chemicals’ mutagenic activity. The spontaneous mutation level of test strains is a mandatory characteristic that has to be monitored in a laboratory performing mutagenicity studies using the Ames test. In this regard, it is important to assess the factors affecting the spontaneous mutation level in the experiment and, therefore, on the general conclusion on the test item mutagenicity. Material and methods. A plate incorporation test version was used both in the presence and absence of a metabolic activation system. Results. We summarized the historical control data obtained in the laboratory in 2016-2020, determine the fluctuation limits in the number of revertant colonies for each strain, and identify the factors affecting the negative control variability. No significant differences were found in the spontaneous background of test strains when using DMSO or water as solvents, polypropylene or polystyrene tubes, as well as Petri dishes of different types. In the case of the TA1535, TA102 and TA100 cultures, no influence of the presence of the S9 mixture on the spontaneous reversion range was revealed (p≤0.05). Statistically significant differences in the number of spontaneous revertants (at + S9 or -S9) were found for the strains that allow detecting frameshift mutations, TA97 and TA98. It has been shown that the volume of the selective medium and the brand of gelling agent in its composition are important factors leading to the variability of the historical negative control. Conclusion. To ensure the quality of experiments according to the principles of good laboratory practice and the reliability of the data obtained using the bacterial reverse mutation method, it is necessary to standardize the operations in advance of experiments.
С использованием теста Эймса и микроядерного теста in vivo на эритроцитах млекопитающих изучена генотоксичность некоторых фосфорорганических пестицидов, применяемых в сельском хозяйстве. Технические продукты хлорпирифоса и диазинона не проявляли генотоксичности ни в условиях in vitro, ни in vivo. Выявлены слабые мутагенные эффекты диметоата на штаммах бактерий. Некоторые технические продукты глифосата, диметоата, а также пиримифос-метил индуцировали цитогенетические нарушения у мышей линии CD-1. Наблюдаемые эффекты in vivo были низкими даже на уровне максимальных переносимых доз, поэтому все исследованные фосфорорганические пестициды могут быть отнесены к 3 или 4 классам опасности по критерию «мутагенность» согласно принятой в Российской Федерации классификации. The genotoxicity of some organophosphate pesticides applied in agriculture was studied using the Ames test and the mammalian erythrocyte micronucleus test in vivo. Technical grade active ingredients (TGAI) of chlorpyrifos and diazinon did not show genotoxicity either in vitro or in vivo. The weak mutagenic effects of dimethoate were revealed with bacterial strains. Some TGAIs of glyphosate, dimethoate, and pyrimifos-methyl induced cytogenetic abnormalities in CD-1 mice. The observed effects in vivo were low even at the maximum tolerated doses. Therefore, according to the pesticide hygienic classification adopted in the Russian Federation all studied organophosphate pesticides can be assigned a 3 or 4 class of hazard upon the criterion “mutagenicity”.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.