Immunofluorescence Imaging of Gastrointestinal Tissues

Immunofluorescence was performed as previously described (Qi et al. 2017 (link)). Briefly, the antrum tissues from human, mouse, rat and pig were washed in cold PBS and were fixed in 4% paraformaldehyde for overnight at room temperature. Then paraffin-embedded antrum sections were de-paraffinized in xylene and dehydrated by a graded alcohol series, followed by antigen retrieval. Next, after washing by PBS for 3 times, the sections were blocked and permeabilized by 0.3% Triton X-100 and 5% BSA for 1 h at room temperature. Then, the sections were incubated with primary antibodies overnight at 4 °C. The fluorescein-labeled secondary antibodies (Life Technologies, 1:300) and 4′, 6-diamidino-2-phenylindole (DAPI) were added for 1 h at room temperature next day. The images were acquired from Olympus FV3000 Laser Scanning Microscope.