Neher and Sakmann heard single ion channels through a suction-sealed glass pipette

By the early 1970s most physiologists believed ions crossed the cell membrane through specific pores, but nobody had seen one. Hodgkin and Huxley had inferred channels from squid axons in 1952, yet a decade-long dispute over their very existence still ran on, because a single channel carries only a few picoamperes — about a billionth of what conventional microelectrodes could cleanly resolve — buried in leak and thermal noise. The standard response was to amplify more and average longer.

At the Max Planck Institute for Psychiatry in Munich, Erwin Neher and Bert Sakmann pressed a glass micropipette a few micrometers wide against a denervated frog muscle fiber and recorded what crossed the patch under the tip. In their 1976 Nature paper the seal was poor — pipette resistance of a few megohms and seals in the tens to hundreds of megohms — but discrete, step-like currents of a few picoamperes showed up anyway: the first recording of a single native channel, which immediately ended the dispute about whether channels exist.

The trick that made it routine was the gigaseal. Fire-polishing the pipette tip and applying mild suction made the membrane cling to the glass so tightly that sealed resistance jumped from the hundred-megohm range into the tens of gigaohms (Hamill, Marty, Neher, Sakmann and Sigworth, 1981). Background noise fell by orders of magnitude, and the same glass grip survived ripping the patch off the cell, giving the cell-attached, whole-cell, inside-out and outside-out configurations that still standardize the field.

Press glass to the cell; suction makes a gigaohm seal

Seal resistance sets the leak: at tens of gigaohms nearly all patch current flows into the amplifier instead of escaping around the pipette rim.

Noise scales with the leak conductance, so a thousandfold tighter seal silenced the background that hid picoampere steps.

Suction-polished glass needed only tools already on the bench — a microforge and a syringe — rather than new electronics.

The grip survived excision from the cell, turning one trick into four standard recording configurations.

When the signal cannot be made bigger, shrink the noise: the breakthrough was not a better amplifier but removing every parallel escape path, so the one remaining path carried the whole story.

The patch clamp became the workhorse of channel biophysics: kinetics, selectivity filters and gating sensors were resolved at the single-molecule level, and pipette-recorded capacitance steps let Neher watch single vesicles fuse during secretion. Ion channels moved from hypothesis to one of the largest drug-target classes; the Nobel Assembly noted the method was already used by thousands of scientists worldwide when it awarded Neher and Sakmann the 1991 Nobel Prize in Physiology or Medicine. Automated patch clamping now runs thousands of cell recordings a day in pharmaceutical screening.