Intracellular location of H. pylori in infected macrophages. Confocal micrographs of primary human macrophages infected with H. pylori NL103 immune stained with rabbit anti-H. pylori serum/donkey anti-rabbit FITC conjugate (green) and nuclear DNA stained with DAPI (blue). The size and shape of macrophages are defined by dashed white lines. H. pylori are located at the cell surface/periphery at 0 and 15 minutes after infection (A), at an intermediate position between the cell periphery and the nucleus (cytoplasmic) 30 minutes after infection (B), and in a peri-nuclear location two and four hours after infection (C). Scale bar = 5 μm.