Hello HengChiat, Could be that the brief exposure to air resulted in more nucleation sites. You could still measure data on your crystal of interest despite the presence of the tiny crystals, as they are not likely to diffract well enough to interfere with the primary diffraction pattern. I would just go ahead and loop and flash-cool the crystal and let the X-rays tell you the answer. If this is the case you need not worry about preventing the tiny crystals from growing.
Good luck! -pam ==============Original message text=============== On Wed, 10 Jun 2009 12:20:55 pm CDT HanJie_HCT Tai wrote: Hi, My crystal was grown in 33%MPD/0.2M (NH4)2SO4/5% P400/0.1M tris in 500 ul well covered with 200ul paraffin oil. The droplet (0.9 ul protein + 0.9 ul reservoir + 0.2 ul 30% DMSO) is hung over the cover slide. Because of twining issue, when the small but single crystal showed up from the drop after overnight setting up, I transferred the cover slide to 30% MPD condition well IMMEDIATELY. (When crystal gets older, it tends to grow into multilayer form, stacking plate lies on the first crystal) HOWEVER, after inspecting under microscope, I found that there were tremendous tiny crystals surround those single crystals :( Any suggestion to improve this situation in order to avoid introducing any tiny crystal in the drop. Additional Q: Should I include 3% DMSO in my cryosolution? Regards, HengChiat _________________________________________________________________ Windows Live SkyDrive: Get 25 GB of free online storage. http://windowslive.com/online/skydrive?ocid=TXT_TAGLM_WL_SD_25GB_062009===========End of original message text=========== -- ---- Pamela J. Focia, Ph.D. Research Assistant Professor Structural Biology Facility Manager Robert H. Lurie Comprehensive Cancer Center in the Departments of: Molecular Pharmacology and Biological Chemistry, Feinberg School of Medicine, and Biochemistry, Molecular Biology & Cell Biology, Northwestern University 303 E. Chicago Ave., S-215, Chicago 60611 (312)503-0848 fax (312)503-5349 [email protected]
