Fig 3. Morphologic and differential characterization of the intestinal epithelium on the gut-on-a-chip platform. (A) The longitudinal section of chip and the immunofluorescence images of cells cultured in gut-on-a-chip with fluidic force, in which expression of ZO-1 (red) at different height could be observed. Corresponding to the schematic, I represents apical side and sequentially V represents basal side. Besides, nuclei are dyed by Hoechst (blue) while F-actin is marked by phalloidin (green), the same below. (Scale bar: 50 μm). (B)Cross-sectional view of expression of ZO-1 in static chip (top) and perfused chip (below). (Scale bar: 100 μm). (C) The integral 3D image of intestinal cells layer in static chip (top) and perfused chip (below). (D) Expression of MUC-2 in perfused chip (Scale bar: 50 μm). (E) The height of villi measured by Image J according to the side view of immunofluorescence. (F&G)Cross-sectional view of expression of Villin and Ki67 in static chip (F) and perfused chip (G) (Scale bar: 50 μm).