Function of an ion-selective electrode using the example of rumen
This method utilizes very small glascapillaries to puncture intact epithelia, allowing the investigator to directly measure the membrane potential. If the membrane expresses an ion channel, the membrane potential will change if the concentration of the ion in the bath solution is changed.
It is also possible to melt and twist two adjoined capillaries to form a double-barrelled electrode. One barrel can then be used to measure the potential of the cell while the other barell can be filled with an ionophore that allows a measurement of the intracellular pH.