Construction, Theory, and Practical Considerations for using Self-referencing of Ca2+-Selective Microelectrodes for Monitoring Extracellular Ca2+ Gradients

Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Methods in Cell Biology 99 (2010): 91-111, doi:10.1016/B978-0-12-374841-6.00004-9.
Ca2+ signaling in the extra- and intracellular domains is linked to Ca2+ transport across the plasma membrane. Non-invasive monitoring of these resulting extracellular Ca2+ gradients with self-referencing of Ca2+-selective microelectrodes is used for studying Ca2+ signaling across Kingdoms. The quantitated Ca2+ flux enables comparison with changes to intracellular [Ca2+] measured with other methods and determination of Ca2+ transport stoichiometry. Here we review the construction of Ca2+-selective microelectrodes, their physical characteristics and their use in self-referencing mode to calculate Ca2+ flux. We also discuss potential complications when using them to measure Ca2+ gradients near the boundary layers of single cells and tissues.
NIH:NCRR grant P41 RR001395