Hi Catherine, At the Hauptman-Woodward Medical Research Institute High Throughput Crystallization Screening laboratory we've just introduced SONICC and UV two photon fluorescence into the imaging process. I don't think it's been announced on the website (http://www.hwi.buffalo.edu/faculty_research/crystallization.html) but the images are now being sent to users routinely and they are proving extremely useful in identifying (a) salt from protein and (b) protein crystals that were not otherwise noticed due to obscuration by precipitate or other gunk. I highly recommend the application of these two techniques in your case. If you don't have it available locally, while trying not to advertise, it is available to the community as a service - just don't ask me! The lab can be contacted directly at hts...@hwi.buffalo.edu<mailto:hts...@hwi.buffalo.edu>.
Cheers, Eddie Edward Snell Ph.D. Assistant Prof. Department of Structural Biology, SUNY Buffalo, Senior Scientist, Hauptman-Woodward Medical Research Institute 700 Ellicott Street, Buffalo, NY 14203-1102 Phone: (716) 898 8631 Fax: (716) 898 8660 Skype: eddie.snell Email: esn...@hwi.buffalo.edu Telepathy: 42.2 GHz Heisenberg was probably here! From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Bishop, Catherine E. Sent: Wednesday, July 16, 2014 10:56 AM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Salt! I have been attempting to obtain a protein crystal of my protein for just over 2 years at this point. We have attempted removing the tag, binding the protein to its ligand, removing as much salt as possible (crashes at at too low a salt concentration)--this lead us to try reverse vapor diffusion--seeding, additive trays, optimization around the conditions an ortholog of one of the domains crystallized well in, and a plethora of other methods. We do get crystals, but they all diffract as salt. Most of these salts are found in wells containing a cation (ie. lithium sulfate, nickel chloride, magnesium acetate, cobalt chloride, etc.). When crystals are too small to shoot, I do set up optimized trays; however, if I get larger crystals, they diffract as salt as well. Most of these set ups, at this point, have also been conducted in hands other than mine and at other facilities known for their successful crystallization of proteins. Has anyone else run into this problem and seen light at the other side?? Any suggestions are appreciated.
