Have you experienced how Nickel-charged chromatography columns used for purifying His-tagged proteins lose their blue color, become a bit yellow and can’t bind your protein anymore? It can happen after only one use. No amount of washing will return it to normal function. As if this isn’t enough, EDTA and/or DTT in the sample and/or buffers will drag the Ni ions out from the resin that will then become white and lose binding capacity.
Suppliers have been working hard to develop resins that are resistant to addition of the DTT and EDTA that His-tagged proteins need in order to remain in an active form. Bio-Works has now succeeded in this and has just launched a new resin called WorkBeads NiMAC (available in bulk but also in prepacked formats as BabyBio NiMAC 1 ml and 5 ml columns). The nickel on our new WorkBeads NiMAC resin is attached so strongly you can purify large volumes of His-tagged proteins from sources containing chelating and reducing agents and not have to worry about Ni ion leakage.
You can use with up to 20 mM DTT and 20 mM EDTA in the sample/buffers without losing any binding capacity and the resin can be used many times.
So, the solution in this case is rather simple, just switch to WorkBeads NiMAC! It’s revolutionizing His-tagged protein purification and it’s also cheaper than some obvious alternatives.