(A) shows a typical case of conductivity (2,4-Dnp, p = 3.3 × 10−7 cm/s; stock solution in DMSO) depending linearly on the concentration (constant permeability). Each circle represents the mean conductivity of several voltage sweeps; the error bars mark their mean SD. Only data points at final DMSO concentrations below 1% v/v (shaded circles) were used in the linear regression (Eq. 10; IGOR Pro). (B) shows a typical case of saturating conductivity (dino2terb, p = 1.1 × 10−4 cm/s; stock solution in DMSO). At low concentration, the mean specific conductivity Gs,0 depends linearly on the concentration (constant permeability), but with increasing concentration, the conductivity saturates (decreasing permeability). Only the part showing linear dependence (shaded circles) was used in the linear regression (Eq. 10; IGOR Pro).