Fig. 3. Effect of the pH of the imaging solution on the occupancy. Topographic images of the p6 2D Ax5 crystal obtained in aqueous solutions containing 150 mM NaCl and 10 mM CaCl2 at different pHs, which were (a) 10 mM MES-K buffer solution (pH 6.0), (b) 10 mM phosphate buffer solution (pH 7.0), and (c) 10 mM Tris–HCl (pH 8.0).
