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 col ony-forming ability were measured after 1 hr of incubation with nine e nvironmental chemicals from different substance classes. The sensitivi ty of the method of determining inhibition of growth was similar to th at of the test of colony-forming ability and was double that of a comm only used method to determine cell survival. Linear regression analysi s showed that the three methods correlated well with each other, the s trongest correlation being between colony-forming ability and growth.