Bio-Rad Nuvia™ IMAC Resin - Manual (Page 5)

Nuvia IMAC Ni-Charged Resin 1
Section 1
Introduction
Immobilized metal affinity chromatography (IMAC) is a powerful
purification technique that relies on a molecule’s affinity for certain
metals immobilized onto a chelating surface. The chelating
ligand, nitrilotriacetic acid (NTA) in this case, may be charged with
transition metals such as Cu
2+ , Ni 2+ , Co 2+ , or Zn 2+ . This results in
high selectivity for proteins with clustered histidine residues to be
strongly retained on a porous chromatographic support.
The use of IMAC to separate an expressed recombinant protein
fused with a hexahistidine peptide tag was demonstrated
by Hochuli (1988) to yield a highly purified protein in a single
chromatographic step under both denaturing and native
conditions. The strong affinity of a histidine-tagged molecule for
metal ions often makes extensive optimization unnecessary while
also allowing chromatography under conditions that denature
proteins. For this reason, expression and IMAC purification of
histidine-tagged proteins is frequently used for structural and
functional studies of proteins.