Immunofluorescent staining of organoids can be performed to visualize molecular markers of cell behavior. For example, cell proliferation marked by incorporation of nucleotide (EdU), or to observe markers of intestinal differentiation including paneth cells, goblet cells, or enterocytes (see Figure 1). In this protocol we detail a method to fix, permeabilize, stain and mount intestinal organoids for analysis by immunofluorescent confocal microscopy.


Figure 1. A schematic depicting a crypt-villus forming organoid, and visualization of Paneth cells by immunofluorescence staining. Left: Small intestinal organoids grow as crypt-villus structures that contain all of the multiple differentiated lineages of the intestine. Right: Immunofluorescent staining can be used to visualize individual cell types in the organoid. Here paneth cells are visualized by staining for lysozyme (“Lyso,” Green), which reveals Paneth cells located at crypt bases. F-Actin (Red) reveals crypt structure at the apical surface of the epithelium, and DAPI (Blue) reveals cell nuclei. Scale bar is 25 μm.