Lipid bilayers are the main structural component of any cell membrane. They contain a variety of lipid types, diverse proteins, and structures which influence the properties and function of the cell and the membrane itself. The complexity of such systems poses a challenge when investigating isolated processes occurring in lipid bilayers. Working with proteins reconstituted in artificial membranes or native, purified membrane fragments are both strategies to reduce the complexity of such studies. Artificial bilayer recordings reveal the actions of single ion channels in real-time, thereby gaining detailed insights into ion channel function, and how bilayer or buffer compositions affect the ion channel. Proteins involved in membrane transport, however, are generally low-conducting. Here, a capacitive read-out from the transporter population has proven successful, either from liposomes or native membrane fractions immobilized on a solid-supported membrane-coated electrode. The Orbit and the SURFE2R product families offer complete control over experimental conditions beyond physiological constraints, allowing in-depth knowledge of parameters affecting membrane function.
Artificial lipid bilayers offer an ideal model system for the electrophysiological investigation of ion channels, porins, and other pore-forming species including toxins or artificially designed nanopores. Planar lipid bilayers separating two aqueous compartments offer a nonconductive matrix for membrane-active molecules. The placement of two electrodes on either side of the membrane, which contains embedded molecules, enables the application of precise voltages and the recording of sub-picoampere level ionic currents. These can be detected by state-of-the-art low-noise amplifiers enabling the precise investigation of single molecules.