Fig. 3. Colocalization of MT-bound early endocytic vesicles with increasing concentrations of antibodies against Rab4 and Rab5. Monoclonal antibodies against Rab4 or Rab5 at increasing concentrations were perfused into a chamber containing MT-bound Texas-Red–ASOR-labeled vesicles, incubated for 6 minutes and visualized after addition of Cy2-labeled secondary antibody. The plot indicates percent colocalization between MT-bound Texas-Red–ASOR vesicles with Rab4 and Rab5 antibody at the indicated concentrations.