The activity of a single ion-channel protein

Has been detected with a new method. Ion channels act like pores with doors that allow ions to flow in and out of cells. That ionic current is how cells exchange information in various neural, cardiovascular, intestinal, and reproductive processes. The standard patch-clamp method for studying ion channels uses the tip of an electrolyte-filled micropipette that is connected to an amplifier. Now, scientists from the University of Munich, Germany, have replaced the pipette with micron-sized holes drilled into a glass chip. They use gentle suction to position and seal an individual cell onto a hole so that an ion-channel protein in the cell’s membrane protrudes out the bottom. The researchers believe that this flat architecture will facilitate an automated bionanotechnological approach to ion-channel research. They add that the planar geometry also enables the combination of scanning-probe techniques or high-resolution fluorescence microscopy with simultaneous electrical recording.(N. Fertig et al., Appl. Phys. Lett. 81, 4865, 2002 http://dx.doi.org/10.1063/1.1531228 ).