New Research Validates Miniaturization of Micronucleus Testing for Genotoxicity by 96-Well Flow Cytometry, Gentronix, collaborating with Litron Laboratories, Janssen Pharmaceuticals and the Novartis Institute for Biomedical Research has published a flow cytometric method of scoring 96-well plate micronucleus testing (MNT) for in vitro screening of compounds for genotoxicity hazards.
Published in Experimental and Molecular Mutagenesis, the paper describes the optimization of the protocol and includes an inter-laboratory assessment of the assay’s transferability and reproducibility. The conclusion of the paper was that the 96-well plate-based MicroFlow® micronucleus test is transferrable across laboratories, and the high information content provided by flow cytometry helps to guard against irrelevant positive results arising from overt toxicity.
The inclusion of the micronucleus test in the recent ICH revision to the guidelines on genotoxicity is evidence of the benefits of using this assay as an alternative to the traditional Chromosome Aberration test. In addition to the assay’s ability to detect aneugens, the use of double staining in the flow cytometry protocol means that apoptotic or necrotic cells can be identified and excluded from the test, thereby guarding against ‘irrelevant positive’ results. Benefits include both an increase in the throughput of the assay and a reduction in the amount of compound required.