Ion-Selective Microelectrodes

PH and ion-selective microelectrodes are rapidly finding an increasing number of applications in the study and control of living (and nonliving) systems. They are unique in their capacity to measure chemical species without altering natural or controlled environmental conditions. Furthermore, these potentiometric tools measure the activity of the chemical species in contrast to conventional ones that measure total concentration. The "Workshop on IonueSelective Microelectrodes" is designed to provide an insight into the principles, theory, fabrication, techniques, present limitations, goals, and applications of some of these tools.The importance and types of microelectrodes and guidelines for their application in biological systems are discussed by Berman. Their present limitations are reviewed by Durst. He warns that their use in analyzing living matter should be approached with caution because of the ill-defined nature of biologic systems. Techniques are presented next for the fabrication of pH (Hebert), antimony (Green and Giebisch, and Malnic et al.), oxygen (Whalen), then single-barrelled (Wright, Walker and Ladle, Morris and rnjevic) and double barrelled (Zeuthen et al., and Khuri) potassium and chloride liquid ion-exchanger microelectrodes. Difficulties with and fabrication of reference and glucose electrodes are covered, respectively, by Durst and Wright, and Bessman and Schultz. Applications of pH and ion-selective microelectrodes are described in microanalysis (Wright), measurement of intracellular ion activity and calculation of equilibrium potentials (Brown and Kunze), and then studies of the kidney (Wright, Malnic et al., and Khuri), brain (Zeuthen et al., Morris and Krnjevic), frog heart (Walker and Ladle), and human skeletal muscle (Filler and Das). In addition, actual and potential clinical applications, respectively, of pH (Filler and Das) and glucose (Bessman and Schultz) electrodes are reviewed. PH and ion-selective microelectrodes are rapidly finding an increasing number of applications in the study and control of living (and nonliving) systems. They are unique in their capacity to measure chemical species without altering natural or controlled environmental conditions. Furthermore, these potentiometric tools measure the activity of the chemical species in contrast to conventional ones that measure total concentration. The "Workshop on IonueSelective Microelectrodes" is designed to provide an insight into the principles, theory, fabrication, techniques, present limitations, goals, and applications of some of these tools. The importance and types of microelectrodes and guidelines for their application in biological systems are discussed by Berman. Their present limitations are reviewed by Durst. He warns that their use in analyzing living matter should be approached with caution because of the ill-defined nature of biologic systems. Techniques are presented next for the fabrication of pH (Hebert), antimony (Green and Giebisch, and Malnic et al.), oxygen (Whalen), then single-barrelled (Wright, Walker and Ladle, Morris and rnjevic) and double barrelled (Zeuthen et al., and Khuri) potassium and chloride liquid ion-exchanger microelectrodes. Difficulties with and fabrication of reference and glucose electrodes are covered, respectively, by Durst and Wright, and Bessman and Schultz. Applications of pH and ion-selective microelectrodes are described in microanalysis (Wright), measurement of intracellular ion activity and calculation of equilibrium potentials (Brown and Kunze), and then studies of the kidney (Wright, Malnic et al., and Khuri), brain (Zeuthen et al., Morris and Krnjevic), frog heart (Walker and Ladle), and human skeletal muscle (Filler and Das). In addition, actual and potential clinical applications, respectively, of pH (Filler and Das) and glucose (Bessman and Schultz) electrodes are reviewed Front Matter....Pages i-viii Front Matter....Pages 1-1 Perspective: Ion-Selective Microelectrodes: Their Potential in the Study of Living Matter In Vivo ....Pages 3-11 Ion-Selective Electrode Response in Biologic Fluids....Pages 13-21 Glass Microelectrodes for pH....Pages 23-38 Some Problems with an Intracellular PO 2 Electrode....Pages 39-41 Some Problems with the Antimony Microelectrode....Pages 43-53 Front Matter....Pages 55-55 Ionic Activities in Identifiable Aplysia Neurons....Pages 57-73 Front Matter....Pages 75-75 Use of Potassium Ion-Exchanger Electrode for Microanalysis....Pages 77-88 Kinetic Analysis of Renal Tubular Acidification by Antimony Microelectrodes....Pages 89-108 Electrochemical Potentials of Potassium and Chloride in the Proximal Renal Tubules of Necturus Maculosus....Pages 109-126 Front Matter....Pages 127-127 Some Measurements of Extracellular Potassium Activity in the Mammalian Central Nervous System....Pages 129-143 Microelectrode Recording of Ion Activity in Brain....Pages 145-156 Front Matter....Pages 157-157 Intracellular Potassium and Chloride Activities in Frog Heart Muscle....Pages 159-171 Front Matter....Pages 173-173 Muscle Ph, PO 2 , PCO 2 Monitoring: A Review of Laboratory and Clinical Evaluations....Pages 175-188 Progress toward a Glucose Sensor for the Artificial Pancreas....Pages 189-197 Back Matter....Pages 199-202