title: Screening ion-channel ligand interactions with passive pumping in a microfluidic bilayer lipid membrane chip.
abstract: We describe a scalable artificial bilayer lipid membrane platform for rapid electrophysiological screening of ion channels and transporters. A passive pumping method is used to flow microliter volumes of ligand solution across a suspended bilayer within a microfluidic chip. Bilayers are stable at flow rates up to ∼0.5 μl/min. Phospholipid bilayers are formed across a photolithographically defined aperture made in a dry film resist within the microfluidic chip. Bilayers are stable for many days and the low shunt capacitance of the thin film support gives low-noise high-quality single ion channel recording. Dose-dependent transient blocking of α-hemolysin with β-cyclodextrin (β-CD) and polyethylene glycol is demonstrated and dose-dependent blocking studies of the KcsA potassium channel with tetraethylammonium show the potential for determining IC50 values. The assays are fast (30 min for a complete IC50 curve) and simple and require very small amounts of compounds (100 μg in 15 μl). The technology can be scaled so that multiple bilayers can be addressed, providing a screening platform for ion channels, transporters, and nanopores.
authors.affiliation: Electronics and Computer Science and Institute for Life Sciences, University of Southampton , Southampton SO17 1BJ, United Kingdom.
authors.forename: Shimul C
authors.initials: SC
authors.lastname: Saha
authors.affiliation: Institute of Structural and Molecular Biology, Birkbeck College, University of London , London WC1E 7HX, United Kingdom.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Powl
authors.affiliation: Institute of Structural and Molecular Biology, Birkbeck College, University of London , London WC1E 7HX, United Kingdom.
authors.forename: B A
authors.initials: BA
authors.lastname: Wallace
authors.affiliation: Electronics and Computer Science and Institute for Life Sciences, University of Southampton , Southampton SO17 1BJ, United Kingdom.
authors.forename: Maurits R R
authors.initials: MR
authors.lastname: de Planque
authors.affiliation: Electronics and Computer Science and Institute for Life Sciences, University of Southampton , Southampton SO17 1BJ, United Kingdom.
authors.forename: Hywel
authors.initials: H
authors.lastname: Morgan