Hi Jahan, Since I can't tell what you tried in terms of improving/optimizing crystallization, here are some methods that my some colleagues and I have had good luck with, in addition to what Gopal has suggested.
(1) Sitting drop technique under oil (2) Varying ratios of protein to precipitant (3) Seeding with several serial dilutions of the seeded material Since you write that you have high mosaicity, perhaps it is also worth double-checking your crystal cryoprotectant and flashcooling conditions. Like Elspeth Garman likes to remind everyone, cryoprotectant and crycooling conditions that mitigate ice formation do not automatically ensure the best diffraction conditions, which often need further optimization. Good luck! Raji On Mon, Oct 15, 2012 at 9:30 PM, Parthasarathy, Gopal <parth...@merck.com>wrote: > During optimization, have you tried Hampton's additive screen? > > Gopal > ________________________________________ > From: CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] On Behalf Of Jahan > Alikhajeh [ja...@graduate.org] > Sent: Monday, October 15, 2012 6:01 PM > To: CCP4BB@JISCMAIL.AC.UK > Subject: [ccp4bb] Plate crystals > > Dear Friends, > > I am trying to crystalize a 70 kDa nasty protein but I got plate shape > crystals with high mosaicity and useless diffraction (up to 4A). > I tried to improve/optimize crystallization but either I got the same or > nothing. I tried seeding but I had so many crystals without any > improvement. Does anyone have better idea than routine optimization method > in the lab? Thanks in advance. > > Jahan > Notice: This e-mail message, together with any attachments, contains > information of Merck & Co., Inc. (One Merck Drive, Whitehouse Station, > New Jersey, USA 08889), and/or its affiliates Direct contact information > for affiliates is available at > http://www.merck.com/contact/contacts.html) that may be confidential, > proprietary copyrighted and/or legally privileged. It is intended solely > for the use of the individual or entity named on this message. If you are > not the intended recipient, and have received this message in error, > please notify us immediately by reply e-mail and then delete it from > your system. -- Raji Edayathumangalam Instructor in Neurology, Harvard Medical School Research Associate, Brigham and Women's Hospital Visiting Research Scholar, Brandeis University
