Order of addition when making the solutions is often important to dilute the least soluble component rapidly. Zn acetate is the most soluble Zn salt. Put that in your tube first and then dilute it with your largets volume (probably either water) and then add the other ingredients, consider vortexing in between additions.
Jim On Fri, May 11, 2012 at 9:26 AM, Rajesh Kumar <ccp4...@hotmail.com> wrote: > Dear All, > > This question sounds simple but I dont know the answer. > I was preparing a 24 well crystal screen. When I try to use 10 mM ZnSO4 > with HEPES (pH 7.6) buffer it precipitates. I tried both ZnCl2 and Zn > acetate the effect is same. > I dont know why this Zn in not compatible with HEPES. > Could you please tell me why is this? > I appreciate your help. > > Thanks > Rajesh > -- * * * James Kiefer, Ph.D. * Structural Biology Genentech, Inc. 1 DNA Way, Mailstop 27 South San Francisco, CA 94080-4990
