I don't know how many of these crystals you have, but if you can spare one try freezing it straight out of the drop without cryoprotection. Certain salts can act as cryoprotectants at high enough concentrations. I don't know about phosphate salts, but I've had crystals that grew in 2.5M ammonium sulfate which I froze without cryoprotection and rarely saw an ice ring in my diffraction.
Good luck, Mike ----- Original Message ----- From: "Jerry McCully" <[email protected]> To: [email protected] Sent: Wednesday, December 15, 2010 1:13:09 PM GMT -08:00 US/Canada Pacific Subject: [ccp4bb] cryoprotectant for protein crystal grown from Di-sodium hydrogen phosphate Dear All; Recently we got some crystals from the condition #51 in the SaltRx crystallization kit from Hampton research. It contains 1.5M Na2HPO4 and 0.1M Tris(pH8.5). We am going to do a test diffraction ASAP. What cryoprotectant did you use for this condition? Thanks a lot and have a nice holiday season! Jinghua -- Michael C. Thompson Graduate Student Biochemistry & Molecular Biology Division Department of Chemistry & Biochemistry University of California, Los Angeles [email protected]
