(color online) DNA molecule electrophoresis mobility, μ, as a fuction of the pH of solution with TIRS 1 mM in different concentrations of cations. (a) DLS for spermidine, (b) DLS for cobex, the concentration of the solution is 0.1 mM (black), 0.3 mM (red), 1 mM (blue), 0.5 mM (green), 2 mM (pink); (c) DLS for spermine, 0.1 mM (black), 0.5 mM (red), 2 mM (blue).