Zetarose NTA FF6 is a 6 % cross-linked beaded agarose resin, derivatized with nitrilotriacetic acid (NTA) ligand. When charged with bivalent metal ions, such as nickel, cobalt, copper, or zinc, the solid phase can be used to purify recombinant proteins containing polyhistidine (polyhistidine-tag) residues via their selective affinity to the chelated metal. After washing, bound proteins are eluted under native or denaturing conditions with either a low pH buffer or with buffer containing imidazole or histidine.