Fig. 3.

CD44 antibody staining of intestinal epithelium. A: EpCAM antibody staining (blue) of the proximal intestine is confined to the epithelium. B: CD44 antibody staining (red) is restricted to the epithelium of the base of the crypt but is also expressed on blood-derived cells located in the crypt and villus mesenchyme. Section is also stained with Hoechst (blue). White dashed line in A and B demarcates the boundary between the epithelium and mesenchyme. C: higher magnification of CD44 staining (red) in the crypt region by confocal microscopy. Laminin (white) is expressed in the mesenchyme. D: EpCAM-expressing (blue) cytospun cells isolated from the epithelial inclusion sorting gate. EpCAM-expressing cells were divided into CD44-expressing (red; E) or CD44-nonexpressing (F). G: there was little variation in the percentages of within the EpCAM⁺ (gate R4), CD44⁺ (gate R5), and CD44⁻ (gate R6) populations across centers. Purity of the CD44⁺ cells was high. Data reported as means ± SE.