Single-channel electrophysiology of cell-free expressed ion channels by direct incorporation in lipid bilayers

Single-channel electrophysiology with lipid bilayer systems requires ion channel expression, purification from cell culture, and reconstitution in proteoliposomes for delivery to a planar bilayer. Here we demonstrate that single-channel current measurements of the potassium channels KcsA and hERG(S5-S6) can be obtained by direct insertion in interdroplet lipid bilayers from microliters of a cell-free expression medium.