Have you tried adding water to your reservoir and allowing it to vapor diffuse into the drop? Kris Kris F. Tesh, Ph. D. Department of Biology and Biochemistry University of Houston
----- Original Message ---- From: Tim Gruene <t...@shelx.uni-ac.gwdg.de> To: CCP4BB@JISCMAIL.AC.UK Sent: Mon, February 28, 2011 3:48:25 AM Subject: Re: [ccp4bb] crystallizing a complex that's sensitive to ionic strength Dear Hua, adding water as suggested by Jan Kern could also be accomplished in a more sophisticated way by using dialysis buttons. They require large volumes, though, 5mul is the minimum as far as I know. At the fancy end of this you could try the TOPAZ system by fluidigm. At the ECM in Darmstadt one of the companies presented a cheap, plasitc based version of this which looked quite appealing to me. Maybe it was the CrystalHarp from Molecular Dimensions, but I am not sure. Cheers, Tim On Sat, Feb 26, 2011 at 09:13:49PM -0500, Hua Yuan wrote: > Dear CCP4 community members, > > I've been trying to crystallize a protein complex that's very sensitive to > ionic strength, i.e., lower salt (~0.3M) will cause precipitation of the > complex but higher salt (~0.5 M) breaks the complex apart. The interaction > that holds the complex is probably mainly ionic type. > The crystals I got so far has only one component of the complex from which > all the crystallization conditions have high salt such as 2M Ammonium > Sulfate in them. Besides repeatly screening many crystallization > conditions, I was wondering whether is any way to work around this problem. > Your suggestions would be greatly appreciated! > > Thanks, > > Hua -- -- Tim Gruene Institut fuer anorganische Chemie Tammannstr. 4 D-37077 Goettingen phone: +49 (0)551 39 22149 GPG Key ID = A46BEE1A
