The PX domain of p47phoxlocalizes at the plasma membrane in resting and stimulated neutrophils. Neutrophils were nucleoporated with the expression vector EGFP-p47-PX or with the EGFP control vector. After 2 h, the cells were stimulated with fMLP (1 μM), PMA (0.1 μg/ml) or left untreated. The cells were then fixed and analyzed for fluorescence distribution by confocal microscopy. The images were processed and analyzed for the distribution of the fluorescent proteins using the NIH image processing and analysis program IMAGE/J software. Scale bars = 3μm. For EGFP-p47-PX, separate cells are shown. For EGFP, the same cells are shown before and after stimulation. The results are representative of three independent experiments.