Real Time Recording of Perifused Chromaffin Cells.

Amperometry is an electrochemical method based on the oxidation or reduction of molecules. Many secretion products, including catecholamines, contain in their molecule chemical groups with the ability to yield (oxidize) or capture (reduce) electrons upon its exposure to an electrical field. In order to measure the secretion of catecholamines, they are oxidized at +650 mV with a carbon electrode, releasing every molecule of catecholamine that is oxidized two electrons (e) that are recorded as an electrical current. Amperometry is an easy-to-use and noninvasive technique for cells (unlike patch-clamp techniques for measuring membrane capacitance) and has been widely used to monitor online catecholamine release from perifused bovine chromaffin cell populations.