The validation of the γH2AX method was carried out in human HepG2 cells with the list of 62 compounds, genotoxic or not, recommended by the European Union Reference Laboratory for alternatives to animal testing (EURL-ECVAM) (Kirkland et al 2008). We have demonstrated that this test allows to detect 95% of the genotoxic compounds tested (against 71% for the Ames test), without false positives compounds (see references, Khoury et al 2013).
The γH2AX/pH3 assay in now under evaluation at the EURL-ECVAM. Discussions at OECD for the use of his method are ongoing.
We have currently tested more than 700 compounds with this assay in different human cell lines.
Results obtained with the γH2AX assay, using the In-Cell Western technique, with the list of ECVAM. Table extracted from our publication "Validation of High-Throughput Genotoxicity Assay Screening Using the γH2AX In-Cell Western Assay on HepG2 Cells".
Comparison with other genotoxicity assays: we have compared the performance of the γH2AX ICW assay with the standard Ames test (Kirkland et al 2008) and the MN assay on HepG2 cells (Westerink et al 2011), using different parameters: sensibility, specificity and predictivity, with the respect to the ECVAM lists of compounds. We found between this three assays a very good correlation, suggesting that the in vitro γH2AX ICW assay could be a suitable test to predict the in vivo carcinogenicity of chemicals.