COMPUTER-CONTROLLED SYSTEM FOR THE REAL-TIME MEASUREMENTS OF MEMBRANE-POTENTIAL, INTERNAL AND EXTERNAL PHS, DELTA-PH, PROTON FLUXES, AND O-2 CONCENTRATION

The construction of sturdy ion-selective electrodes for tetraphenyl phosphonium ion (TPP+), and salicylate is described. Instrumentation and procedures are presented for real-time studies of membrane potentials and pH gradients that form across the membranes of organelles that are capable of transducing metabolic or radiant energy into an electrochemical potential for protons. The system is based on input signals from a TPP+-selective electrode, fluorescence from a pH-sensitive dye, a pH electrode, and an O2 electrode. A microcomputer is used to perform extensive computations based on the raw input data and to display various aspects of the progress of an experiment both on a CRT monitor and a recorder.