FIG. 3.

Basal and induced expression of tested proteins in Tet-OFF MEF cultures. Cultures of two separately selected clones expressing each protein were either incubated in doxycycline (+) or incubated without doxycycline (−) for 48 to 72 h followed by lysis, SDS-PAGE separation, and Western blotting for FLAG tag as described in Materials and Methods. Fifty micrograms of protein was loaded per well. Staining for β-actin in the samples confirmed equal loading.