<p><b>A</b>) Flow cytometry of a spleen homogenate infected with <i>Salmonella sifB::gfp</i> using 488 nm excitation. Gate 1 contains GFP-positive <i>Salmonella</i>. The inset shows the relationship between flow cytometry data and plate counts for individual mice, the dashed line represents a 1∶1 ratio. <b>B</b>) Confocal micrographs of liver cryosections infected with <i>Salmonella sifB::gfp</i> that were stained with antibodies to <i>Salmonella</i> lipopolysaccharide (red) and macrophage marker CD68 (blue). Individual color channels are shown with inverted grey scale for better visualization of weak staining. Micrographs represent typical observations for four independently infected mice. <b>C</b>) Confocal micrographs of lipopolysaccharide-positive particles that lack detectable GFP (even when contrast was increased compared to B). Such particles were absent in non-infected control sections.</p
