The low-frequency dielectric properties of biological cells

Abstract

The passive electrical or “dielectric” properties of biological cells have been studied since the last century [1]. Important advances in our knowledge that have accrued from the application of dielectric spectroscopy to biological systems include the recognition of the molecular thickness of biological membranes [2] and of the existence of voltage-gated ion channels as embodied in the Hodgkin-Huxley [3] equations. However, as judged by its complete omission from a book on Biological Spectroscopy [4], the technique has not achieved as widespread a recognition and exploitation in biophysics as it warrants [5]. Notwithstanding, and due in large part to advances in instrumentation which make the acquisition, display and interpretation of biological dielectric spectra much more convenient than has historically been the case, the last 10 or 15 years have seen a significant increase in the use of the technique [5–18a].