Figure 9. Immunolocalization of CE11-related antigen in sections of the canine midcorpus epididymidis. Employing polyclonal CE11 antipeptide antibody, strong immunostaining was observed in the adluminal part of the duct epithelium by the immunoperoxidase technique (a) suggesting apical sorting of CE11 membrane protein. Polyclonal antibody against cytokeratin served as a positive control (b). Preimmune serum was employed as a negative control (c). Staining of apical brush border or stereocilia was prominent also during indirect immunofluorescence (d).