The FRAME multicentre project on in vitro cytotoxicology.

An in vitro method for assessing the relative acute toxicities of chemicals was developed through the collaboration of four tissue culture laboratories. Cytotoxicity was measured by using a dye-binding method to determine inhibition of the proliferation of BCL-D1 cells 72 hr after addition of the test chemical. A blind trial with 50 chemicals showed that the test procedure gave results with a high degree of interlaboratory reproducibility.