COMPARISON OF THE SENSITIVITY OF 3 TOXICITY TESTS DETERMINING SURVIVAL, INHIBITION OF GROWTH AND COLONY-FORMING ABILITY IN HUMAN FIBROBLASTS AFTER INCUBATION WITH ENVIRONMENTAL CHEMICALS

The sensitivity of three methods measuring basal cytotoxicity in human fibroblasts was compared. Cell survival, inhibition of growth and colony-forming ability were measured after 1 hr of incubation with nine environmental chemicals from different substance classes. The sensitivity of the method of determining inhibition of growth was similar to that of the test of colony-forming ability and was double that of a commonly used method to determine cell survival. Linear regression analysis showed that the three methods correlated well with each other, the strongest correlation being between colony-forming ability and growth.