Figure 4: FBS/BSA blocks the binding of EGCG to intracellular proteins. HepG2 cells were cultured in serum-free medium or in the medium with different concentrations of FBS/BSA for 1 hr and then treated with 60 μM EGCG for 9 hrs with the presence of FBS/BSA. Cell lysates were collected for Western blot. (a) The several proteins, including caspase-3, PARP, and α-tubulin, can be readily detected again in SDS-PAGE with increased concentrations of FBS/BSA in the culture medium. (b) Quantitative analyses of protein expression are presented as means ± SD (). , compared to the serum-free group.