I forgot to mention a phenomenon when I did crystal mounting. I found that if open a coverslip, phase separation will appear in drops in minutes and damage to the crystals.
And I have tried additive screen. The optimized crystals are really big (a few hundred microns) with sharp edge but diffraction pattern is similar. On Tue, Jan 26, 2010 at 10:42 AM, Zhiyi Wei <ustcwebri...@gmail.com> wrote: > Dear all, > > I got a problem with my crystals. I have two total different proteins > that both can be crystallized in the condition with PEG3350 and Tacsimate > (although the concentrations are different) with different shapes. The > crystals look big and beautiful. However, when I test them in synchrotron, > both of these two types of crystals showed poor diffractions. As showed in > the attached diffraction image, the diffraction is up to ~4 A but smear in > one direction while <8 A in the other direction. The interesting thing is > that the diffraction pattern is similar for all crystals (from two different > proteins) that I tested without exception although they belong to different > space groups. So, I wonder whether these kind of pattern is caused by > Tacsimate (I don't know what it is) and how to rescue these crystals. Any > suggestions or comments? > > Thanks a lot! > > Best, > Zhiyi >
