a. Go with phase diagram gradually changing concentrations of protein, precipitant, salt concentrations and pH. Find where you are going out of crystallisation. Define region for streak seeding. b. Screen for ratios of precipitant to protein from 1:9 to 9:1.
Dr Felix Frolow Professor of Structural Biology and Biotechnology, Department of Molecular Microbiology and Biotechnology Tel Aviv University 69978, Israel Acta Crystallographica F, co-editor e-mail: mbfro...@post.tau.ac.il Tel: ++972-3640-8723 Fax: ++972-3640-9407 Cellular: 0547 459 608 On Feb 25, 2013, at 18:02 , lei feng <spartanfeng...@hotmail.com> wrote: > Hello everyone, > I need your suggestion for slowing down crystallization for my protein > my protein got hit in PEG/ION #5 ( 0.2 M MgCl2, 20% PEG 3350, pH 5.9), but it > crystallize too fast. In 1 hr I can see tons of tiny needles. > Can anyone give me some suggestion on how to slow down the process? I used > lower conc. of potein, lower conc. of PEG ( 10%), it helped a little bit, > giving me small rod crystal. but no improvement after that. > > Thank you very much for your suggestions