Fig. 4.

Co-induction of luciferase and Oatp1 expression correlates with enhancement of bioluminescence. HEK 293T and HCT116 cells were transfected with a plasmid (pTRE3G-LO) expressing luciferase and Oatp1 from a doxycycline-inducible promoter. a Enhancement of bioluminescence, following addition of luciferin (89 μΜ), was dependent on the doxycycline concentration used to induce expression (n = 3, error bars show SD). Western blot showing induction of luciferase, and hence Oatp1, at increasing doxycycline concentrations in b HEK 293T cells and c HCT116 cells.