Nicotinic receptor-mediated catecholamine secretion from individual chromaffin cells. Chemical evidence for exocytosis.

Simultaneous detection of vesicular content and exocytotic release with two electrodes in and at a single cell

“…Exocytosis is typically measured by placing a carbon-fibre disk microelectrode in close contact to the surface of a single cell. 26 However, as the tip of a disk electrode (diameter > 5 μm) occupies a relatively large surface area when it is being put on a PC12 cell (diameter around 10–15 μm), it interferes with placement of the other electrode. Since the quantification of exocytotic release shows no significant difference between disk and nanotip electrodes, 28 we chose to use nanotip electrodes to measure both release and storage.…”

“…A variety of techniques are capable of visualizing or measuring exocytotic release, among which is single-cell amperometry (SCA). 26 SCA offers ideal temporal resolution, down to sub-millisecond level, to resolve individual release events and meanwhile is the only approach that allows the quantification of the number of released molecules. 27 In addition, SCA is a relatively simple method, especially when it comes to measuring the release of electroactive neurotransmitters, such as dopamine, norepinephrine and serotonin.…”

Three Distinct Modes of Exocytosis Revealed by Amperometry in Neuroendocrine Cells

“…For almost 20 years, investigators have used carbon-fiber microelectrode amperometry to measure exocytosis from single neuroendocrine cells (6). Amperometry has unparalleled sensitivity and time resolution, and has been successfully used to detect differences in the amount of neurotransmitter secreted per vesicle or in fusion kinetics, which are reflected in spike characteristics.…”

Electrogenerated chemiluminescence detection of single entities

“…In the past decades, single-entity analysis (SEA) became a prevalent area in analytical chemistry. 1–5 It refers to the study of individual “entities and processes” which could be a nanoparticle, a molecule, a cell, or a reaction. SEA seeks to separate individual responses from the bulk.…”