[Measurements of the potential difference during adsorption of phloretin and fluorescein on the surface of lipid membranes using the method of inner field compensation].

The inner field compensation method was used for the measurement of the boundary dipole potentials as a function of phloretin and fluorescein concentration, ionic strength and pH. These potentials were compared with calculated from the conductance change in the presence of nonactin. Both methods gave similar results for fluorescein, but the steady-state potentials in the case of phloretin, obtained by the first method were smaller. These results imply that fluorescein, being introduced on one side of the BLM, remained on that side contrary to phloretin which penetrated through the membrane and partitioned between its both boundaries.