Dear Frank, Here you mentioned the saturated stock 3M is at room temperature or not. Since at room temperature now I can make 2.5 M stock at most at about 22 degredd celsius.
Thank you very much for your good suggestion. Donghui On 2/27/08, Francesco Rao <[EMAIL PROTECTED]> wrote: > > Hi Donghui, > > Have you tried a higher concentration of Lithium Sulfate? Try a > saturated (~3M) stock and make sure your crystals is in it for less > than 20 seconds. I've had a similar crystal condition in the past and > 2 M Li2SO4 didn't cryoprotect. > > HTH > > Frank > > On 26 Feb 2008, at 19:30, wu donghui wrote: > > > Dear all, > > > > Recently, I got a crystallization condition as 0.1 M Bis tris ph > > 6.5, 1.3M lithium sulfate, 0.1M NaCl, the shape of crystals is > > needle cluster, very difficult to grow bigger, microseeding does > > not work, then I tried macroseeding, and found crystal can grow > > bigger and rod like. However as for the cryoprotectant, crystal > > will dissolve in glycerol, ethylene glycol, MPD and PEG, even in > > the very low concentration about 5%. I found my crystal can grow > > under the additive 2-propanol in addition to the above mentioned > > crystallization condition. I also noticed that Hampton > > cryoprotectant kit has the 2-propanol as cryoprotectant. I want to > > know if anyone have ever used 2-propanol as the cryoprotectant and > > what effect it might be. By the way Hampton also mention lithium > > sulfate can be used as cryoprotectant, the recommended maxium > > concentration is 2M, I tried and found ice ring is severe and it is > > very easily to form lithium sulfate salt crystal at this high > > concentration, I also tried sodium malonate, the diffraction gave > > me few spots, resolution is only about 6--7 angstrom. > > > > Does anyone encounter such problem by lithium sulfate? > > > > > > Welcome to any replies. Thanks a lot in advance. > > > > Donghui > > ########################################################## > Dr. Francesco Rao EMBO Postdoctoral > Research Fellow > Dept. of Biochemistry (Rm. 4350) TEL: ++ 1 604 822 7729 > Life Sciences Center FAX: ++ 1 604 822 5227 > 2350 Health Sciences Mall E-mail: > frankr_at_byron.biochem.ubc.ca > University of British Columbia WWW: http://byron.biochem.ubc.ca > Vancouver, BC Canada V6T 1Z3 > >
