Measurement of Voltage Dependence of Capacitance of Bilayer Lipid Membrane under the Existence of Ion Carriers

The capacitance of a bilayer lipid membrane depends on the applied voltage. The difference of the boundary potentials of the two surfaces of the membrane can be obtained by using this property. However the conventional method have not taken the existence of ion-carrier in membrane into consideration. The current of ion-carrier changes nonlinearly by the applied voltage on the membrane, which cause difficulty to measure the voltage dependence of the capacitance. Here a method to avoid such a difficulty is described The validity of the method was checked both by experimentally and by the computer simulation.