-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Dear Jahan,
is your diffraction useless, or do you call 4A resolution useless? 4A is not too bad and can be a start for structure determination while you are waiting for better crystals. You give very little information about what you actually have done, and if you search the bb-archive for "how to get better crystals" you can probably make a book from the number of hits. If you got a large number of crystals while seeding, try harder - the idea of micro seeding is to adjust the conditions below nucleation concentration and seed there. Dilute your cat whisker further until you have only very few seeds left (you may want to have a look at Fig. 11.2.(a) on p. 63 of http://shelx.uni-ac.gwdg.de/~tg/thesis.pdf to get an idea of the effect. If all else fails, you can also try restricted proteolysis, although I would put this in "routine optimization methods" nowadays. Good luck, Tim On 10/16/2012 12:01 AM, Jahan Alikhajeh wrote: > 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 > - -- - -- Dr Tim Gruene Institut fuer anorganische Chemie Tammannstr. 4 D-37077 Goettingen GPG Key ID = A46BEE1A -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iD8DBQFQfQ68UxlJ7aRr7hoRAqsOAKCI5hIkO2VkI4EGEuQQfggWQASFqQCg2BHo 6QaulOnNvPRocZ9r4BlQTVg= =FM/p -----END PGP SIGNATURE-----
