Intracellular crowding prevents cargo diffusion. HeLa cell after uptake of A647-tagged 10 kD dextran treated with 10 µM nocodazole to depolymerize the MTs. As expected, directed movement of the dextran vesicles was completely abrogated. The diffusion of the vesicles was also insignificant, indicating that intracellular crowding likely prevented cargo diffusion away from the MTs. “N” marks the position/direction of the nucleus. Imaged at 50 fps, movie playback 50 fps. Scale bar: 5 µm. Movie related to Fig. S4 f.
