Fig. 1. Dose response curve for the yeast-based human estrogen receptor (hER) assay to synthetic estrogen 17-ethynylestradiol (EE2) dissolved in dimethylsulfoxide (DMSO) solvent in concentrations of 2.9 to 2950 ng L^-1. The response is expressed as a percentage of the mean maximum response elicited by 2950 ng L^-1 of EE2 (n = 8). Note the EC50 (effective concentration to cause 50% of the mean maximum estrogenic response) = 200 ± 25 ng L^-1.