Ni-TED Agarose Resin for IMAC Purification Nickel Resin

Nickel-TED (Ni-TED) Agarose Beads are affinity chromatography resins for the purification of poly-his-tagged recombinant proteins under native or denaturing conditions. The resin consists of the chelating Tris(carboxymethyl)ethylenediamine (TED) groups immobilized on agarose beads. Since the protein binding Ni ions are immobilized through TED groups, the resin is also called Immobilized Metal Affinity Chromatography (IMAC) resin. Our His-Pure Ni-TED resin is based on proprietary super porous agarose resin, which enables fine purification of large proteins or protein complexes. The binding capacity of this resin is in 20-30 mg/ml range depending on the size and binding situations. Although its binding capacity is somewhat lower than the Ni-NTA and Ni-IDA, the resin generates the cleanest result or lowest background. And this resin tolerates EDTA (10 mM or more) and reducing agents (10 mM or more).

There are commonly three types of chelating ligands for IMAC resins, IDA (Iminodiacetic Acid), NTA (Nitrilotriacetic Acid) and TED (Tris(carboxymethyl)ethylenediamine). You may choose or try some of them based on your situation. 

IDA (Trivalent / Tridentate)
• Coordination sites: Uses 3 sites to bind the metal ion, leaving 3 free sites for the protein.
• Pros: Higher protein binding capacity and yield; cheaper; requires less imidazole to elute. Often good for initial capturing.
• Cons: Higher metal ion leaching (bleeding); lower purity because of more non-specific binding. Not compatible with EDTA and DTT.
NTA (Tetravalent / Tetradentate)
• Coordination sites: Uses 4 sites to bind the metal ion, leaving 2 free sites for the protein. It is the most common choice.
• Pros: Higher purity and specificity; lower metal ion leakage; handles harsher buffers well. Tolerates small amount of EDTA and DTT or 2-mercaptoethanol. A well balance between capturing power and clean results.
• Cons: Lower overall yield; stronger binding can make protein elution harder. 
TED (Pentadentate / Tridentate-like strong chelator)
• Coordination sites: Uses 5 sites to bind the metal ion, leaving only 1 free site for protein histidine interaction.
• Pros: Very low or no metal leaching; can tolerate some amount of EDTA and DTT without losing the Ni ion; has lowest purification background.
• Cons: Lowest binding capacity for the protein due to fewer open sites for the His-tag; Lower capturing power.