Effects of As₂O₃ and DHA on intracellular Bax expression of HL-60 cells. Cells were treated with 1 μM As₂O₃, 25 μM DHA, or the combination of both substances for 24 hours. After treatment, cells were washed, permeabilized, and stained with an unconjugated monoclonal anti-Bax antibody, followed by a FITC-conjugated secondary antibody. Data are expressed as contour plots of the forward scatter image (x-axis) plotted against Bax fluorescence intensity (y-axis) of a representative experiment.