Electron microscopy of neutrophils from skin windows after phagocytosis of latex beads.

(A) Cryosection incubated with anti–hCAP-18 and 10-nm protein A-gold. Neutrophil with phagolysosomes (p) containing latex beads. (Inset) Higher magnification of the marked area showing a granule containing hCAP-18 (large arrow) and a phagolysosome also labeled for hCAP-18 (small arrows). Bars, 400 nm; inset, 100 nm. (B) Double-immunogold labeling of hCAP-18 (as a marker of specific granules) with 10-nm gold particles and myeloperoxidase (MPO, as a marker of azurophil granules) with 5-nm gold particles demonstrated that both azurophil and specific granules fused with the phagolysosome. Bar, 100 nm.