Patch clamp

The patch clamp technique is a laboratory technique in electrophysiology that allows the study of single or multiple ion channels in cells. The technique can be applied to a wide variety of cells, but is especially useful in the study of excitable cells such as neurons, cardiomyocytes, muscle fibers, and pancreatic beta cells. It can also be applied to the study of bacterial ion channels in specially prepared giant spheroplasts.

The patch clamp technique is a refinement of the voltage clamp. Erwin Neher and Bert Sakmann developed the patch clamp in the late 1970s and early 1980s. This discovery made it possible to record the currents of single ion channel molecules for the first time, which improved understanding of the involvement of channels in fundamental cell processes such as action potentials and nerve activity. Neher and Sakmann received the Nobel Prize in Physiology or Medicine in 1991 for this work.

Patch clamp recording uses a glass micropipette called a patch pipette as a recording electrode, and another electrode in the bath around the cell, as a reference ground electrode. Depending on what the researcher is trying to measure, the diameter of the pipette tip used may vary, but it is usually in the micrometer range. This small size is used to enclose a membrane surface area or "patch" that often contains just one or a few ion channel molecules. This type of electrode is distinct from the "sharp microelectrode" used to puncture cells in traditional intracellular recordings, in that it is sealed onto the surface of the cell membrane, rather than inserted through it.

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