I assume (if not, no wonder you get less binding and selectivity over time) you regenerate your NTA material with the various steps recommended e.g. increasing and decreasing EtOH series ? Regeneration buffer (6M Guanidiniumhydrochloride 0.2 M acetic acid) 1%SDS and lots of water, EDTA and 100 mM NiSO4 or CoSO4 or MnCl2 or FeCl2 or ZnCl2
Yes you can charge other metals and the selectivity will vary depending on the metal, the binding capacity should not vary if you use the same amount of resin. Typically you get purer proteins with Co compared to NI. The Agarose superflow material is I think the same for Talon (Clontech) and Qiagen, not sure about Machery & Nagel or Sigma's product. Jürgen. - Jürgen Bosch Johns Hopkins Bloomberg School of Public Health Department of Biochemistry & Molecular Biology Johns Hopkins Malaria Research Institute 615 North Wolfe Street, W8708 Baltimore, MD 21205 Phone: +1-410-614-4742 Lab: +1-410-614-4894 Fax: +1-410-955-3655 http://web.mac.com/bosch_lab/ On Jul 22, 2010, at 10:05 PM, Matthew Bratkowski wrote: > Hi. > > We have been using His-Select Resin from Sigma in our lab for a number of > years now. When we first bought the resin, I usually got much better purity > of His tagged proteins compared with regular Ni-NTA resin. However, after > regenerating the resin several times, the level of purity seems to have > declined. Has anyone else noticed this with His Select? In general, could > someone suggest the typical "lifespan" of His Select or Ni2+ resin in > general? What about Glutathione resin? > > I was also wondering if anyone had experience using cobalt resin? What is > the binding capacity of cobalt compared to nickel, and is the selectivity any > better than either His-Select or regular Ni-NTA? Also, is it possible to > just strip nickel off of the resin and then recharge it with cobalt? > > Thanks, > Matt
