Figure 3

Estradiol binding to HeLa cells stably transfected with ERα. Subconfluent HeLa-ERα cells were trypsinized and aliquots (2 × 10⁶ cells) incubated with several concentrations of ³H-17β-estradiol in the presence and absence of a 200-fold excess of cold 17β-estradiol for 30 min at 37°. Cells were then incubated on ice for 15 min, washed three times with 2 ml of ice cold 0.2% BSA-saline and pelleted by centrifugation at 1,5000 rpm for 10 min at 4°C. Cells were lysed by the addition of 100 ul of lysis buffer, vortexed and counted. a) Representative binding results of 3 independent experiments with total binding (solid box), non-specific binding (open box), and specific binding (triangle). b) Scatchard analysis of binding results.