Patch amperometry measures the patch membrane capacitance. In this mode the sensitivity of capacitance measurements increases more than 10 fold, compare to whole cell recordings, because the capacitance in cell attached is dominated by the small capacitance of the membrane patch. Release of the exocytotic fusion events occurs into the patch pipette. Therefore, To monitor release of catecholamines from these granules the electrochemical detector needs to be placed inside the patch pipette (figure)

Inverted amplifier settings in patch amperometry. The bath is driven with the Vcommand of the "head stage" of the patch clamp amplifier and the ground electrode is located in the pipette filling solution. This makes a better reference for the carbon fiber.

 Permanent and reversible fusion events measured in chromaffin cells in patch amperometry. Reversible fusion events were obtained by increasing the extracellular (only in the patch) calcium concentration to tens of mM. (see Nature Cell Biology 1, 40-44, 1999)