Fig. 1.

Representative immunoblots of heat shock protein 70 (Hsp70) expression in cells in the presence of distinct concentrations of doxycycline (Doxy; 0, 0.001, 0.1, and 2 μg/ml). Total protein lysates (312.5 ng) were used, followed by SDS-PAGE and immunodetection with Hsp70 MAb. A: samples from double-stable HeLa cells expressing a tetracycline-controlled transactivator protein and transfected with the plasmid pTRE2hyg-HSP70 (hyg = hygromycin). A set of known amounts of standard Hsp70 (50–200 ng) was loaded in parallel. B: samples derived from nontransfected cells treated the same way as transfected cells serving as controls.