One approach is to try modifying your current condition with additives.
We have had some occasional successes with polyol, salt, or solvent
additives modifying crystal morphology from needles to something more
tractable. Hampton research has a good list of 10X additives in their
catalog. In our most recent one we converted 10x10x200 um needles into
20x100x100 um plates that diffracted nicely. The addition of 100 mM
AmSO4, 5% EG, or 100 mM KNa tartrate to our original conditions (mostly
PEG4000) all worked well. 5% DMSO worked slightly less well.
shivesh kumar wrote:
> Dear all,
> I am trying to crystallize a 7kDa protein with MPD as a precipitant.I
> got the needles with precipitation in two days at 30% and in 4-5
> days,needles appear in all the drops(pH 3.8-4.8).The concentration of
> protein is around 20mg/ml and the volume of mother liquor in
> 500microlt.What should I do to get good crystals,the temp. I am trying
> is 16C.Thanx in advance for the suggestions.
> Shivesh Kumar
--
------------------------------------------------------------------------
Roger S. Rowlett
Professor
Colgate University Presidential Scholar
Department of Chemistry
Colgate University
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Hamilton, NY 13346
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