Ion selective microelectrodes: computer-controlled calibration, plotting, and data analysis.

Calibration of ion-selective microelectrodes involves delivering and measuring the potential of several different solutions both before and after intracellular measurement. A microprocessor-controlled system is described which completely automates that tedious process. The microcomputer controls the delivery of the calibration solutions and prints out the calibration value along with the solution number. A second program plots the calibration curve using a modified Nicholsky equation and a third program converts intracellular ion signals into ion concentration. Specific examples based on Ca-selective microelectrodes are shown.