Immunohistochemical Staining of Pancreatic Tissue

Immunohistochemistry was performed at the Pancreas Research Laboratory of the University of Zürich, using a previously established protocol (35 (link), 36 (link)). Briefly, sections of formalin-fixed, paraffin-embedded pancreatic tissue were deparaffinised, boiled in citrate for antigen demasking, and blocked prior to incubation with the primary antibody directed against human REG1A or REG3A, respectively, at a 1:800 dilution. Following incubation with the biotinylated secondary antibody (Dako Cat# P0141), avidin and biotinylated enzyme (Vectastain ABC kit, Vector Laboratories, Cat#PK-4000), sections were stained with 3,3-diaminobenzidine tetrahydrochloride dihydrate, counterstained with hematoxylin (Dako, Cat#CS70030-2), and coverslipped.