Probing the membrane potential of living cells by dielectric spectroscopy

TL;DR

This study introduces a dielectric spectroscopy method to quantitatively measure live cell membrane potential, aligning well with traditional dye-based techniques, and demonstrates its application on E. coli with controlled potassium chloride variations.

Contribution

The paper presents a novel dielectric spectroscopy approach for measuring membrane potential in live cells, validated against established methods.

Findings

Dielectric spectroscopy accurately measures membrane potential.

Results agree with voltage-sensitive dye measurements.

Method effectively detects potential changes induced by potassium chloride.

Abstract

In this paper we demonstrate a quantitative way to measure the membrane potential of live cells by dielectric spectroscopy. We also show that the values of the membrane potential obtained using our technique are in good agreement with those obtained using traditional methods-voltage sensitive dyes. The membrane potential is determined by fitting the experimental dielectric dispersion curves with the dispersion curves obtain from a theoretical model. Variations in the membrane potential were induced by modifying the concentration of potassium chloride in the solution of the cell suspension in the presence of valinomycin. For exemplification of the method, E. coli were chosen for our experiments.