Ni-NTA Agarose is a nickel-charged affinity resin that can be used to purify recombinant proteins containing a polyhistidine (6xHis) sequence. Proteins bound to the resin may be eluted with either low pH buffer or by competition with imidazole or histidine. One-step purification can be performed under both native and denaturing conditions. Ni-NTA uses the chelating ligand nitrilotriacetic acid (NTA) coupled to a cross-linked 6% agarose resin that is suitable for use in batch and gravity flow applications.