Fig. (2) Schematic representations of several automated pipette-based patch-clamp technologies. The pipette electrode moves to contact the surface of a randomly chosen cell that is suspended in a layer within a density gradient (A) or at the air/liquid interface (B). (C) A cell is positioned on the recording pipette electrode using negative pressure at the suction channel. (D) Cells are flushed into a pipette and are pushed into the inside tip of the pipette.