Experimental setup for conducting the patch-clamp technique. (A) Sample cell immersed in external recording solution within a recording chamber attached via a glass micropipette that forms a gigaseal with the plasma membrane. The micropipette contains an internal recording solution connecting the cell interior to the feedback resistor and recording apparatus via a silver electrode. Current flow measured during a patch-clamp experiment is equal and opposite to the micropipette current. (B) Different configurations of the conventional patch-clamp technique allowing recordings to be made on excised patches: the inside-out mode (top-right), made by pulling the membrane patch off the cell into the bath solution, and the outside-out mode (lower-right), made by applying suction (lower-left) to destroy the membrane isolated by the patch pipette and then pulling the pipette away from the cell.