Figure 12.

Double labeling of endocytic compartments. JAS-pretreated cells were incubated with FITC-dextran added to the basolateral chamber for 15 or 30 min at 37°C and then stained with primary antibodies followed by Cy3-conjugated antibodies. An antibody against rab5, a marker for early endocytic compartments, did not colocalize with any of the vesicles labeled with FITC-dextran after 15 min uptake (a and b). rab7 (c and d) and M6PR (e and f), markers for late endosomes, showed no colocalization with FITC-dextran after 30 min uptake. TRITC-transferrin showed partial colocalization with labeled compartments in the basal region of the cells but not in the middle region after uptake for 15 min (g and h). Green, FITC-dextran; red, specific antibody or TRITC-transferrin; M, middle region; B, basal region. Bar, 10 μm.