Fig. 5.

Amperometric measurement of fusion pore dynamics. (A) A CFM is placed close to the cell and a voltage of typically 700 mV is applied. (B) Amperometric current from a single fusion event in a chromaffin cell [54]. The amperometric current reports the flux of catecholamine molecules from the vesicle. Amperometric spikes are typically quantified by quantal size, half width, mean foot current and foot duration as indicated. The foot current reports fusion pore properties as shown in Fig. 6.