Interference of electron donors in the measurement of the proton gradient and membrane potential by flow dialysis.
The three most commonly used electron donors for flow dialysis measurements of membrane potential lead to the development of an apparent but artifactual membrane potential with the interior negative in the presence or absence of membrane vesicles. The same three electron donors used in flow dialysis determinations of delta pH in the presence or absence of membrane vesicles lead to the development of an apparent but artifactual delta pH with the interior acidic. These artifacts have been evaluated using two probes for membrane potential, namely, TPP+ and rubidium in the presence of valinomycin and for two probes of delta pH, namely, acetate and DMO. Measurements were made over a range of ionic strengths.
D003956:Dialysis / Q000379:methods; D004579:Electron Transport; D004926:Escherichia coli / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D008433:Mathematics; D008564:Membrane Potentials; D011865:Radioisotope Dilution Technique; D013104:Spheroplasts / Q000502:physiology
D007202:Indicators and Reagents