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Self-referencing, non-invasive, ion selective electrode for single cell detection of trans-plasma membrane calcium flux

Smith, Peter J.S., Hammar, Katherine, Porterfield, D. Marshall, Sanger, Richard H. and Trimarchi, James R. (1999) Self-referencing, non-invasive, ion selective electrode for single cell detection of trans-plasma membrane calcium flux [in special issue: Calcium Identification] Microscopy Research and Technique, 46, (6), pp. 398-417. (doi:10.1002/(ISSN)1097-0029). (PMID:10504217).

Record type: Article


Biological systems have very different internal ion compositions in comparison with their surrounding media. The difference is maintained by transport mechanisms across the plasma membrane and by internal stores. On the plasma membrane, we can classify these mechanisms into three types, pumps, porters, and channels. Channels have been extensively studied, particularly since the advent of the patch clamp technique, which opened new windows into ion channel selectivity and dynamics. Pumps, particularly the plasma membrane Ca2+-ATPase, and porters are more illusive. The technique described in this paper, the self-referencing, ion-selective (or Seris) probe, has the ability to monitor the behavior of membrane transport mechanisms, such as the pumps and porters, in near to real-time by non-invasively measuring local extracellular ion gradients with high sensitivity and square micron spatial resolution.

The principles behind the self-referencing technique are described with an overview of systems utilizing ion, electrochemical and voltage sensors. Each of these sensors employs the simple expedient of increasing the system resolution by self-referencing and, thereby, removing the drift component inherent to all electrodes. The approach is described in detail, as is the manner in which differential voltage measurements can be converted into a flux value. For the calcium selective probes, we can resolve flux values in the low to sub range. Complications in the use of the liquid ion exchange cocktail are discussed. Applications of the calcium selective probe are given, drawing on examples from the plant sciences, developmental biology, muscle physiology, and the neurosciences.

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Published date: 29 September 1999
Keywords: ion transport, porter, atpase, potassium, hydrogen, seris probes, ionophore, ion-selectivity, response time, liquid membrane


Local EPrints ID: 190519
ISSN: 1059-910X
PURE UUID: 5d85140c-fefb-413e-9f88-4bafaf782b83
ORCID for Peter J.S. Smith: ORCID iD

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Date deposited: 15 Jun 2011 12:11
Last modified: 18 Jul 2017 11:38

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Author: Katherine Hammar
Author: D. Marshall Porterfield
Author: Richard H. Sanger
Author: James R. Trimarchi

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