> On Mar 29, 2017, at 4:15 PM, Chun Luo <c...@accelagen.com> wrote: > > In addition to price, the prevalence of Ni purification may be another reason > for Tris popularity. Some His-tagged constructs don't bind to Ni well in > HEPES. I wonder if anyone has similar experience or comments. —Chun
No, I have not specifically noted that before. Additionally, why would you use a positively charged buffer on a weak cation exchange resin? The Ni affinity resins, in addition to their noteworthy affinity for various metals, are also weak cation exchange resins. Binding a positively charged buffer to a negatively charged column material can cause pH effects that you probably weren’t expecting. Tris may have some uses. But using it in a mobile phase with Ni affinity columns or as a final sample buffer aren’t the best cases for choosing Tris. I understand it is widely used in aquaculture applications where they are treating tens of thousands of gallons of water, and price of the buffer substance is an actual consideration. Craig
