Perspective: Ion-Selective Microelectrodes: Their Potential in the Study of Living Matter In Vivo

Abstract

Work with ion-selective macro- and microelectrodes is rapidly evolving into a new specialty area in biology. The inherent advantages of the approach are basic: it enables one to measure activity of an ionic species directly, as opposed to concentration, and it does this simply, quickly, and in the presence of numerous other components in a complex system, negating the need of first isolating the molecular or ionic species of interest. Interfering species can be compensated for in most cases. Selective microelectrodes have the additional unique potential of making measurements of ionic species possible for the first time in vivo under conditions that approach normalcy, and, in addition, in a continuous manner. Net reactions can therefore be followed in vivo. In contrast, most biochemical measurements today are based on in vitro procedures that are nonphysiologic. Furthermore, they are frequently limited to only one point in time. Undoubtedly piercing a cell with a microelectrode can alter its functional state. But, as has been debated in neuro- and electrophysiology, if the microelectrodes are sufficiently fine and the area entered small with respect to the total cell, then the injury should be negligible and the measured activity should approximate that present in the normal living system.

The Organizers and Participants of the “Workshop on Ion-Selective Microelectrodes” acknowledge with thanks sponsorship by the Microcirculatory Society and Boston University, and support by the National Heart and Lung Institute, Labtron, Microelectrodes, Inc., and the Transidyne General Corporation.