Friday, September 21, 2007

Patch Clamp: "Gigaseal"

This is an excerpt from Neher's Nobel Lecture for 1991 (He won that year's prize for Physiology/Medicine) concerning the "gigaseal"

click here for the full text of his lecture

"When Bert Sakmann and I started measurements by placing pipettes onto the surface of denervated muscle fibres, we soon realized that it was not so easy to obtain a satisfactory 'seal'...our initial attempts failed. Our seal resistances were just about 10-20 MQl, two orders of magnitude lower than desired."
...
"We made many systematic attempts to overcome the seal problem (manipulating and cleaning cell surfaces, coating pipette surfaces, reversing charges on the glass surface etc.)
with little success. "
...
"By about 1980 we had almost given up on attempts to improve the seal, when we noticed by chance that the seal suddenly increased by more than two orders of magnitude when slight suction was applied to the pipette. The resulting seal was in the gigaohm range, the so-called 'Gigaseal'. ...Fortunately, Fred Sigworth had just joined the laboratory. With his experience in engineering he improved the electronic amplifiers to match the advances in recording conditions. Thus, several types of ion channels could be characterized rapidly at good amplitude and time resolution."

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