2.6.1.100	recombinant His-tagged BtrR from Escherichia coli strain BL 21 (DE3) by cobalt affinity chromatography, gel filtration, and anion exchange chromatography	
2.6.1.100	recombinant His-tagged BtrR from Escherichia coli strain BL21 (DE3) by nickel affinity chromatography and gel filtration