Fig. 1.

Estimation of relative levels of ERα and ERβ using real-time PCR on cDNA prepared from T47D ERβ cells. (a) T47D ERβ cells cultured on six-well plates were treated with different tetracycline concentrations. After 12 h, RNA was prepared, cDNA was synthesized, and real-time PCR was performed by using ERα- and ERβ-specific primers. Each point represents three different treatments. (b) Whole-cell extracts were prepared from 100-mm plates with T47D ERβ cells treated with different concentrations of tetracycline for 12 h. Western blotting was done with 25 μg of protein FLAG antibody to detect tagged ERβ, and β-actin antibody was used as loading control.