CD 68 positivity of the so-called meconium corpuscles in human foetal intestine.

CD 68 antibodies are most frequently used as a reliable paraffin marker of histiocytes. The CD 68 clusters of antibodies recognize a 110-kDa glycoprotein associated with lysosomes and therefore these antibodies show visible reactivity with cells of the monocyte/macrophage lineage. We observed distinct CD 68 positivity of granular intraepithelial inclusions in the small intestine of 12-week-old human foetuses. These PAS positive inclusions corresponded to the so-called meconium particles, whose lysosomal origin was confirmed by electron microscopy. Our new observation shows that CD 68 antibodies are specific mainly for organelles and not for a cell type and therefore the staining of epithelial cells containing lysosomes is possible.