ECVAM prevalidation of three cell transformation assays.

A prevalidation study on the cell transformation assays in SHE cells at pH 6.7, SHE cells at pH 7.0 and Balb/c 3T3 cell line was coordinated by ECVAM focussing on issues of standardisation of protocols, within-laboratory reproducibility, test method transferability and between-laboratory reproducibility. The Validation Management Team concluded that standardised protocols are now available that should be the basis for future use. The SHE pH 6.7, and the SHE pH 7.0 protocols and the assays system themselves are transferable between laboratories, and are reproducible within- and between-laboratories. For the Balb/c 3T3 method, some clarifications and modifications to the protocol were needed to obtain reproducible results. Overall, three methods have shown to be valuable to detect rodent carcinogens.