Dear Acoot, Just to add to other good ideas, you could also try to index your frames, find the cell parameters, check them against one of the relevant databases (CSD, ICSD; see <http://www.iucr.org/resources/data> or COD, <http://www.crystallography.net/index.php>, which unfortunately is still not listed at that IUCr page) or have a friend run them for you, if you don't have access.
Chances are you might even find out what your salt is from the cell dimensions, which might give you some directions at reducing relevant concentrations or changing some other parameter of technique. (And, by the way, if the cell parameters are novel, you might even have a new compound--e.g. a new set of ligands around the metal center. In that case, just measure your data out to 1.2 A or better, preferably at least 0.83 A--doable on an ordinary home Cu source meant for protein crystallography--solve, refine and publish it.) Best regards, Navdeep --- On Sun, Dec 01, 2013 at 07:16:06PM -0800, Acoot Brett wrote: > Dear All, > > Suppose I have a crystal hit from the protein-metal complex, with the > possibility of that the hit is a salt crystal. When I diffract it by X-ray, I > got some metal (or salt) diffraction without the protein diffraction (maybe > due to too low protein resolution). Will you please tell me how to know > whether my diffraction was from a salt crystal or from the diffraction of the > metal in my protein-metal complex? > > I am looking forward to getting your reply. > > Cheers, > > Acoot --- Navdeep Sidhu University of Goettingen ---
