5 80 0.17 M NaCl 8 buffer (160 ml) to buffer + 0.4 M NaCl (160 ml) Column chromatography _ 6 crib220u270rib220u1882i 20 mM Tris-HCl, pH 8.0 anion exchange column chromatography (TOSOH CORPORATION, Super Q TOYOPEARL 650M)