Hi Rafael, If it has not been already suggested: try DMSO (20% to 40%).
In my limited experience I found that often DMSO works well for crystallization conditions with high-salt or high buffer component (like >1M D,L,-Malic acid). HTH, -Partha On Thu, Dec 17, 2009 at 1:39 PM, Meitian Wang <meitian.w...@psi.ch> wrote: > good point! recently we managed to collect very good room temperature > data with PILATUS detector at SLS. if your crystals are large enough, say > 100 microns or so, you have chance. regards, meitian > > > On Dec 15, 2009, at 1:42 PM, mjvanraaij wrote: > > why not stay with room temp? > many structures have been solved at RT... > > > Mark J. van Raaij > Dpto de Bioquimica, Facultad de Farmacia > Universidad de Santiago > 15782 Santiago de Compostela > Spain > http://web.usc.es/~vanraaij/ > researcherID: B-3678-2009 > > > > > > > On 15 Dec 2009, at 13:20, Natalie Zhao wrote: > > -----Original Message----- > > From: owner-c...@dl.ac.uk [mailto:owner-c...@dl.ac.uk] On Behalf Of Rafael > Couñago > > Sent: 14 December 2009 20:22 > > To: c...@ccp4.ac.uk > > Subject: [ccp4]: TDS upon flashcooling > > > Dear all, > > > I got these beautiful looking crystals that grow in high salt (1.8M) and > > diffract under 2.0A at room temp. My attempts so far to cryo protect > > them have resulted in a loss of resolution (2.5A tops) and increased > > anisotropy. > > > I have tried some of the usual suspects; no cryo, ethylene glycol, > > glycerol (even 5% makes my crystal crack), sucrose, glucose, paratone-n > > (no diffraction at all). I have tried both dipping the crystal straight > > into liquid nitrogen and flash cooling it in the cryostream. > > > An interesting observation is that the diffraction pattern following > > freezing has a substantial amount of thermal diffuse scattering (but no > > ice rings). If I remove the crystal from the cryostream and re-anneal > > it at room temp (in air or in mother liquor or mother liquor + cryo) > > most of the TDS goes away, but the max resolution is still around 2.5A > > and the higher anisotropy is still there. Extending re-annealing times > > lead to cracking of the crystal. > > > My two questions would be: > > > - any thoughts on cryo solutions? > > - does the result from the re-annealing experiment ring any bells? > > Would this be an indication that I need the cooling to be faster or slower? > > > Cheers, > > > Rafael. > > > -- > > Rafael Couñago > > Research Fellow > > Department of Biochemistry > > University of Otago > > > 710 Cumberland St > > Dunedin, New Zealand > > ph: (03) 479 5148 > > > -- > > Scanned by iCritical. > > > __________________________________ > Meitian Wang > Swiss Light Source at Paul Scherrer Institut > CH-5232 Villigen PSI - http://sls.web.psi.ch > Phone: +41 56 310 4175 > Fax: +41 56 310 5292 > >
