Supplemental Figure 1.

Air-liquid interface (ALI) culture generates a compact, clumped-appearing mucus layer. (A) Schematic of culture formats. (B) Immunofluorescence staining of sectioned monolayers. Green: Muc2; blue: Hoechst 33342. White arrows indicate goblet cells. (C) Scanning electron microscopy images. Top panel: submerged culture. Bottom panel: ALI culture. (D) The mucus layer was overlaid with 1-μm red fluorescent beads (top, red) or GFP-expressing EC (bottom, green). The nuclei of intestinal cells were stained with Hoechst 33342 (blue/aqua). The yellow dashed line shows the boundary between the mucus and microbeads or EC. A, apical; B, basal.