ISO 21427-2:2006规定了使用哺乳动物体外试验测定水和废水遗传毒性的方法，该试验检测水溶性物质对中国仓鼠V79细胞染色体或有丝分裂器的损伤。 微核试验可以识别导致细胞遗传学损伤的物质，从而形成含有滞后染色体片段和/或整条染色体的微核。 该分析基于微核细胞在有代谢活化和无代谢活化的情况下孵化后的频率增加。

ISO 21427-2:2006 specifies a method for the determination of genotoxicity of water and waste water using a mammalian in vitro test which detects damage, induced by water-soluble substances, to the chromosomes or the mitotic apparatus of V79 cells from the Chinese hamster. The micronucleus test allows the identification of substances that cause cytogenetic damage which results in the formation of micronuclei containing lagging chromosome fragments and/or whole chromosomes. The assay is based on the increase in the frequency of micronucleated cells after incubation with and without metabolic activation.