Label-free detection of mitochondrial activity with Microwave Dielectric Spectroscopy Research Article

Abstract

International audienceMitochondrial bioenergetics contributes to important biological processes and its dysfunction underlies some diseases, but its assessment requires invasive methods involving intracellular staining and chemical inhibitors. In this study, we introduce microwave dielectric spectroscopy (MWDS) as a new non-invasive and label-free method to detect mitochondrial activity in live cells. We show that under electromagnetic radiation with microwaves (0.4-40 GHz), the dielectric properties of living cells are determined by their mitochondrial activity. MWDS instantly detects the mitochondrial depolarization induced by drugs targeting electron transport chain complexes or during the earliest events of the apoptotic process, from a cell suspension of a single microliter. MWDS also discriminates cancer cells with higher mitochondrial activity, an aspect often related to therapeutic resistance in cancer. Thereby, MWDS represents a highly innovative method for non-invasive detection of mitochondrial activity in live cells, with a broad range of applications in biology and medicine