Fig. 3. Endocytic transport and lysosomal degradation of EGF is retarded by Fab fragments specific for endobrevin, vti1b, syntaxin 7 and syntaxin 8. HeLa cells were microinjected with Fab fragments specific for cellubrevin, endobrevin, vti1b, syntaxin 7 and syntaxin 8. EGF labeled with the fluorescent dye Texas Red was then added. After binding of EGF, endocytotic transport was allowed to proceed for 1 (left) or 3 h (right). At the end of the incubation, the cells were fixed and analyzed by fluorescence microscopy. Microinjected cells were identified by the nuclear staining by co-injected DAPI. Bar, 10 µm.