Protocol for measuring transcytosis and recycling of IgG in intestinal epithelial Caco-2 cells and primary human intestinal organoids

Transcytosis is the primary mechanism by which macro-molecules transverse epithelial cell barriers. Here, we present an assay for measuring transcytosis and recycling of IgG in intestinal epithelial Caco-2 cells and primary human intestinal organoids. We describe steps for establishing human enteroids or Caco-2 cells and plating monolayers. We then provide procedures for a transcytosis and recycling assay and a luciferase assay. The protocol facilitates quantification of membrane trafficking and can be used to probe endosomal compartments unique to polarized epithelia.