NTA versus IDA: what's the difference?
Cube Protocols & Datasheet
If you are using immobilized-metal affinity chromatography (IMAC) to purify proteins, there is a good chance your metal ion is coupled to the resin matrix via either nitrilotriacetic acid (NTA) or iminodiacetic acid (IDA). There are other chelating ligand used for IMAC resins, but NTA and IDA are the popular ones. Which chelating ligand do you use and why? Does it make a difference? To help our customers make an informed purchasing decision, we took our PureCube Ni-NTA Agarose and PureCube Ni-IDA Agarose and put them under the magnifying glass (figuratively, of course).
How do the two ligands differ structurally and chemically?
How does chelating ligand impact binding capacity?
What role does the metal ion play in resin affinity and specificity?
How do NTA and IDA respond to oxidizing agents?
Does a chelator in the sample buffer impact NTA and IDA differently?
NTA vs. IDA: a tale of two ligands
ABSTRACT. Immobilized metal affinity chromatography (IMAC) is a popular method for protein purification, particularly for recombinant proteins fused to a polyhistidine tag.Transition metal ions immobilized to a matrix through a chelating ligand interact with the polyhistidine tag, effectively sequestering the fused protein from a sample. Nitrilotriacetic acid (NTA) and iminodiacetic acid (IDA) are two such ligands commonly used in commercially available resins. In this application note we summarize our knowledge, from publications and in-house experiments, regarding the differences, advantages, and disadvantages of the two ligands. We present a few basic principles that should underly the purchase of a resin to optimize purification results.