Figure 4.

Examples of single docking and fusion events. Mean Rh-DOPE fluorescence intensities from single vesicles observed under s-polarized excitation (A) and p-polarized excitation (B) are plotted as a function of time. The intensities were extracted from 5 × 5-pixel² areas around the vesicle. Time zero represents the time point at which the vesicles docked to the supported membrane. It is characterized by a sharp increase of the mean intensity in both cases. The onset of fusion is characterized by a second sharp increase in intensity for s-polarized excitation (A) and by a sharp drop in intensity for p-polarized excitation (B) (arrows in insets).