RIKEN Research Center for Allergy and Immunology View Institution's Website 1 article published in JoVE Immunology and Infection Application of a Mouse Ligated Peyer’s Patch Intestinal Loop Assay to Evaluate Bacterial Uptake by M cells Shinji Fukuda1, Koji Hase1, Hiroshi Ohno1 1Laboratory for Epithelial Immunobiology, RIKEN Research Center for Allergy and Immunology M cells in a specialized follicle-associated epithelium covering Peyer’s patches play an important role for the mucosal immunosurveillance in gut-associated lymphoid tissue. Here we described the evaluation method for bacterial transcytosis by M cells in vivo. This method provides a method to understand M-cell function in the immune system.