Cells express different ion channels and transporters with specific ion selectivity and permeability on the membrane and the lipid bilayer is impermeable to ions (Fig 1). Thus, there exists a measurable membrane potential across the cell membrane with negative voltage inside the cell compared to outside. A cell that is more negative in comparison to the extracellular space is considered hyperpolarized and when it becomes less negative it is considered depolarized. Interestingly, cancer cells are depolarized when compared to normal cells and events like apoptosis are associated with further depolarization without repolarization. Thus, alteration in membrane potential can serve as a unique bioelectrical signal/marker of cellular events. In this proposal we aim to develop a simple detection system for alterations in membrane potential indirectly by sensing local changes in ionic concentrations. For this purpose, we use ion sensing electrodes which will be connected to the Arduino unit. With this system, ultimately, we hope to develop a low cost, easy and fast way of detecting alterations in cellular states in response to drugs blocking ion channels or inducing apoptosis.
Jyotsna Rao, Cancer Research UK- Cambridge Institute
Jyotsna Rao will contribute the knowledge of cell culture and alterations in ionic concentrations that lead to altered membrane potential in different cellular states. She will assist in designing and building the prototype and also perform the experiments.
Alan Wright, Cancer Research UK- Cambridge Institute
Alan Wright will contribute the knowledge detecting the local changes in ionic concentrations using ion sensing electrodes and its integration with the Arduino kit. He will design and build the prototype and assist in performing the experiments.