Firdous, Many crystallographers (if not all) went through case like you describe. So far you’ve got great suggestions that are worth trying. I’ll add one more from my own experience. In all cases I tried it appeared that addition of 0.5 to 1% v/v of glycerol or ethylene glycol to drop (either having it added to protein solution or to precipitant mix) doesn’t change “crystallizability” of the protein. However, that minor presence of the cryo agent in the solution where crystals grew allows increasing the concentration of cryo agent to 20-25% during harvesting, which should be enough for cryopreservation.
Good luck. Regards, Vaheh Oganesyan, PhD www.medimmune.com From: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> On Behalf Of Firdous Tarique Sent: Friday, October 19, 2018 5:58 PM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] suggestions for cryoprotectant Dear members I have got beautiful crystal hits in SaltRx screens which are not diffracting to a good resoultion. All of them are salt based condition and I am not able to formulate a good cryoprotectant for these crystals. I also think that in my case the poor resolution is due to a poor cryoprotectant selection. The conditions are as follows: 1> 4M Ammonium Acetate 100mM Bis Tris Propane pH 7.0 2>0.5M KCN 100mM Tris pH8.5 3>1.5M LiSo4 100mM Bris Tris Propane pH 7.0 4>4M Sodium Nitrate 100mM Tris pH8.5 5>1.5M Sodium Nitrate 100mM Sodium acetate pH 4.6 There are few more conditions but so far not able to see good diffraction with using lower peg and glycerol based cryoprotectants. Can anybody suggest me good cryos conditions for salt based crystallization conditions or anything good for SaltRx crystallization hits. Thanks Firdous ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1<https://clicktime.symantec.com/a/1/RZ-6ononTf2Da61sqhx7Eckwa_6wyR_tpzqY3TgWCUM=?d=56SwbeWRqYdRm9Vgr_apGUmjV_mSALCSOWiBOWjY4-nqsVgFRWqNawCATDTt8qWYE-Mu2MEzGeFKt3WkcTTguYsIKqpd_ccr68WdIZjNlomU1dkOmo0fjcsPJX75RXBd-UdNKJlySuGrA-jexrYSxap8kxikznIy2I0nBM3pzJKsw6d0j2yGbIIJP3ygr3dpjxO7jRaV-eL31RoVGM6JXdZEu-Hm7dVJ6fQobk6O86WEpiqsOmLdqz4RC6OPVi0QPlUwQ0HNhT_9n7_HI1Oy-GwsEwg1Mg6xW8kHftkLUNHrYxgewPi8F4XrSh-9zo_aGvtQL-aHQte2H-EEfgrSJg726E2HL8If4RBhRii5Ssvql0PXV9ChKKbE8vVJQ6SaKXbVzmysAkUpWjzHSPM_KbbZlKu9SLtGBC4%3D&u=https%3A%2F%2Fwww.jiscmail.ac.uk%2Fcgi-bin%2Fwebadmin%3FSUBED1%3DCCP4BB%26A%3D1> To the extent this electronic communication or any of its attachments contain information that is not in the public domain, such information is considered by MedImmune to be confidential and proprietary. This communication is expected to be read and/or used only by the individual(s) for whom it is intended. If you have received this electronic communication in error, please reply to the sender advising of the error in transmission and delete the original message and any accompanying documents from your system immediately, without copying, reviewing or otherwise using them for any purpose. Thank you for your cooperation. ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
