Since water is unbuffered, you are likely changing the pH of the solvent, desorbing additional protein. If you are working unbuffered, your IEX results will be unpredictable.
Roger Rowlett On Sep 29, 2011 4:55 AM, "K Singh" <ksc...@gmail.com> wrote: > Dear All, > Apologies for bit off-topic. I am in process of purifying a protein by > ion-exchange (cation) > using 0.5-3M NaCl gradient. And I get a sharp peak which is western > positive. Following elution, > I wash the column >10 column volume with 3M NaCl. and now when I > wash the column > with water, I get a huge peak which is also western positive. Any > inputs or suggestions explaining > this phenomenon? > Kris
