Immunofluorescence and confocal microscopy analysis of PR3 and αII-spectrin in neutrophils. (A) Immunofluorescence microscopy analysis of neutrophils after PR3 (left) and αII-spectrin (right) immunolabeling (magnification ×63). (B) Confocal microscopy of indirect immunolabeling of αII-spectrin (red) in resting or apoptotic neutrophils. Images were obtained as described in Figure 2. Under both conditions, αII-spectrin was localized at the inner face of the neutrophil plasma membrane and gave a typical membrane pattern different from that of PR3. No evidence of marked colocalization (white) under basal or apoptotic conditions was found. (C) Percentages of PR3–αII-spectrin colocalization calculated with LSM software, based on 407 resting and 85 apoptotic neutrophils from 4 different donors. Data are mean (± SEM).