Figure 7. Determination of the target protein levels. NB4 cells were treated with or without realgar (75.0 μg/ml) for 72 h. The levels of Bcl-2, Bax, Cyt-C, and AIF were measured using immunofluorescence. (A) Cell nuclei were stained with 4',6-diamidino-2-phenylindole (DAPI; blue). (B) The fluorescence intensity of each protein is shown. Original magnification, × **P < 0.01.