Genotoxic effects of chromium(VI) and cadmium(II) in human blood lymphocytes using the electron microscopy in situ end-labeling (EM-ISEL) assay

Evaluation of genotoxic effects of potassium chromate (K2CrO4) and cadmium chloride (CdCl2) was carried out in human blood lymphocytes in vitro as measured by the electron microscopy in situ end-labeling (EM-ISEL). EM-ISEL was used to assess DNA single-strand breaks (SSBs) expressed as number of immunogold particles per mu m(2) of chromatin at both chromosomal and nuclear DNA levels. Human lymphocytes were cultured in supplemented RPMI medium for 72 h including treatment for 2 h with K2CrO4 (0-150 mu M), CdCl2 (0-150 mu M) or methyl methanesulfonate (500 mu M) as a positive control. Quantification of SSBs by EM-ISEL showed that both compounds are genotoxic agents at non-cytotoxic concentrations. This study brings new information on the utility of EM-ISEL for the evaluation of genotoxicity and confirms the genotoxic effects induced by chromium and cadmium. (c) 2005 Elsevier Ltd. All rights reserved.