Immobilized Metal Ion Affinity Chromatography (IMAC), developed by Porath (1975), is based on the interaction of certain protein residues (histidines, cysteines, and to some extent tryptophans) with cations of transition metals.
The Co-NTA Resin is specifically designed for the purification of recombinant proteins fused to the 6 x histidine (6XHis) tag expressed in bacteria, insects, and mammalian cells. The resin is high affinity and selectivity for recombinant fusion proteins that are tagged with six tandem histidine residues. Although 6X His tagged proteins bind with a lower efficiency compared to nickel chelating resins there is a significant reduction in non-specific binding.
The Co-NTA resin can be used to purify 6X His tagged proteins under native and denaturing conditions. Proteins bound to the resin can be eluted with low pH buffer or competition with imidazole or histidine.
The Co-NTA resin uses nitrilotriacetic acid (NTA), a tetradenate chelating ligand, in a highly cross-linked 6% agarose matrix. The NTA binds Co2+ ions by four coordination sites.
This resin has a capacity of 20-40μmoles Co2+/ml resin. The protein binding capacity is >50mg protein per ml resin. We have demonstrated binding of >100mg of a 50kDa 6XHis tagged proteins to a ml of resin.
The spin columns are supplied with a resin bed volume of 0.2, 1 and 3ml with total column volumes of 1, 8 and 22ml respectively. Columns can be used as a spin format of gravity flow columns.
Also available in 96-well spin plate formats for processing up to 96 samples.
Immobilized IDA Nickel
Chelating Resins are also available. Cobalt has the highest selectivity followed by Zinc, Nickel then Copper, but has the lowest loading capacity. Copper has the highest loading capacity, followed by Nickel then Zinc.
Our new HOOK™ 6X His Protein Purification kits are now available and include everything required for purification of 6X His tagged proteins from yeast or bacteria, including lysis buffers, lytic enzymes, resin, columns and binding, wash and elution buffers. Each kit is available with nickel or cobalt chelating resins. Kits available are:
- Uses nitrilotriacetic acid (NTA), a tetradenate chelating ligand
- For the purification of 6x His proteins
- High capacity: >50mg/ml
- Ligand density: 20-40μmoles Co2+ /ml resin
- Bead Structure: 6% cross-linked agarose
- Affinity purification of proteins with a 6x His tag.