Figure 3.

Kinetics of the switching off and on of Tet‐off system in HepG2 (A) doxycycline at 1 ng/ml. (B) Doxycycline at 10 ng/ml. Cells were exposed to doxycycline for 24 hours, 1 day after transfection. Doxycycline was removed for the subsequent 24 hours, and activities were assayed at 0, 1, 3, 6, 12 and 24 hours. Luciferase activities were assayed using Nano‐Glo® dual‐luciferase® reporter (NanoDLR™) assay system (Promega). Readings from each well were normalized to signals from co‐transfected controls (pSV40‐NlucP). Dotted lines depicts the time taken for the luciferase signal to reduce by 50%. Data are reported as the mean ± SEM from triplicate wells in a single experiment.