Nanomaterials have outstanding and unprecedented advantageous material properties but may also cause adverse effects in humans upon exposure. Testing nanomaterials for genotoxic properties is challenging because traditional testing methods were designed for small, soluble molecules and may not be easily applicable without modifications. This review critically examines available genotoxicity tests for use with nanomaterials, including DNA damage tests such as the comet assay, gene mutation tests such as the mouse lymphoma and hprt assay, and chromosome mutation tests such as the micronucleus test and the chromosome aberration test. It presents arguments for the relative usefulness of various tests, such as preferring the micronucleus test over the chromosome aberration test for scoring chromosome mutations and preferring mammalian cell gene mutation tests because the Ames test has limited utility. Finally, it points out the open questions and further needs in adapting genotoxicity tests for nanomaterials, such as validation, reference nanomaterials, and the selection of top test concentrations, as well as the relevance and applicability of test systems and the need to define testing strategies. This article is categorized under: Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials Toxicology and Regulatory Issues in Nanomedicine > Regulatory and Policy Issues in Nanomedicine
