Concentration-responses of BG1Luc and MCF7 cells at CCi to unstressed PC and stressed Tritan™ resin leachates. BG1Luc and MCF7 cells at CCi were incubated with the indicated concentration of E2 (A,B), unstressed PC pellet leachate (C,D) or stressed EX401 Tritan™ resin (E, F) in triplicate wells. Luciferase activity (BG1Luc cells) or proliferation (MCF7 cells) of intra-assay triplicates was determined as described under Materials and Methods and as described for BG1 cells in the legend for Figure 4. Concentration-response data are expressed as the mean ± SD of such triplicate analyses. Solid black lines and data points show agonist activity for all data points not associated with toxicity (see Methods); red lines and data points show results of coincubation of BG1Luc/MCF7 cells with E2 or extracts and 10-8 M ICI. Horizontal dotted line shows the 15%RME2 value that is significantly (p <0.01, Student’s T-test) greater than the VC and SC.