Figure 4: Effect of low or high concentration of AECS/p-BQ on reactive oxygen species (ROS) production in cultured A549 cells and its prevention by vit C. Serum-starved A549 cells grown on coverslips were either nontreated (NT) or exposed to 2 μL/mL AECS, 50 μL/mL AECS, 200 ng/mL p-BQ or 2.5 μg/mL p-BQ for 1 hr with or without vitamin C (40 μg/mL) pretreatment in serum-free medium for 15 min. After treatment, cells were incubated in fresh media containing H2DCFDA for 30 min and PBS washed twice, and fluorescent images were captured.