Patch-damp measurements

Patch damp Measurements On-Chip, Rgure 2 Four configurations of patch clamp... 

Hectrophysiological measurements using the dip stick (6) and patch damp technique (7) were performed with three different preparations of proteoliposomes. Liposomes containing the entire CFqCFj (4), liposomes containing mainly CFg where most of CFj was removed by NaBr treatment (4) and liposomes containing subunit m which had been recovered from SDS gels (4,8). 

Fig. 1 Schematic diagram of the patch-damp technique [5] A heat-polished glass pipette (tip diameter in the order of l jim) is pressed against a clean membrane surface. Upon slight suction a high resistance seal (> 1 GO) forms between the tip of the pipette and the membrane. This high seal resistance and the small membrane area reduce the background noise in such a way, that it becomes possible to measure currents (< IpA) passing through a single ion channel protein. The mechanical stability of the seal between pipette and membrane allows the isolation of the membrane patch encircled by the pipette The withdrawal of the pipette in the attached configuration results in an inside-out patch.

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