Figure 2: ROS production was reduced by FBS/BSA. HepG2 cells were cultured in serum-free medium or in the medium with different concentrations of FBS or BSA for 1 hr and then treated along with 60 μM EGCG for 6 hrs with the presence of FBS or BSA. The intracellular ROS was detected by CM-H2DCFDA and analyzed under a fluorescence microscope. (a) Representative images showing intracellular ROS. (b) Quantitative analyses of intracellular ROS (, mean ± SD). , compared to the serum-free group.