Patch clamp

Patch-clamping is an electrophysiological recording technique that enables the investigation of single ion channel properties. Using patch clamping it is also possible to assess the electrical properties of small cells. Recordings are done with glass microelectrodes, similarly as in intracellular recording (although the electrodes are not so sharp). The electrode glass forms an electrically and mechanically tight attachment to the lipids of the cell membrane, so-called giga-seal (referring to the Gigaohm resistance of the junction).

Depending of the configuration of the cell or cell membrane different variants are in use:

cell-attached clamp

Here the electrode is sealed to the cell membrane allowing investigation of possible ion channel activity on that spot of the membrane.

whole-cell clamp

Here the opening of the cell-attached part of the membrane is for voltage-clamping the whole cell or recording its responses in current-clamp mode

outside-out

Here the configurations where the cell patch is pulled from the cell, allows its detailed study.

History

Invention of patch-clamping is credited to Neher and Sakmann (1976) who got the Nobel prize in 1992 for this innovation.