The patch clamp measures current flow through ionic channels in natural membranes; these proteins control membrane function in cardiac muscle. Measurements are significantly limited by the available electronics. This is particularly true in the case of the resistor (( 5 X 10*10 ohm) needed to measure the current of ( 10*-12 ( flowing through just one channel molecule. The new patch clamp circuit will use a small capacitor instead of the resistor. Prototypes show feasibility and much improved properties in all specifications tested so far.In Phase I, a complete instrument will be built and biological measurements will be taken from a variety of muscle preparations in all configurations of the patch clamp. In Phase II, the patch clamp amplifier will be turned into a practical and commercial product and a prototype of a similar instrument-optimized for physical scientists-will be built and marketed.National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
