Re: [ccp4bb] Off topic: ask about cryoprotectant selection using lithium sulfate as precipitant for crystal growth

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From: Darren Thompson D {- dot -} Thompson {- at -} SUSSEX {- dot -} AC {- dot -} UK
Date: 2008-02-27

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Subject: Re: Off topic: ask about cryoprotectant selection using lithium sulfate as precipitant for crystal growth
From: Jim Pflugrath jim {- dot -} pflugrath {- at -} RIGAKU {- dot -} COM
Date: 2008-02-27

Subject: Re: Off topic: ask about cryoprotectant selection using lithium sulfate as precipitant for crystal growth
From: Christian Biertuempfel biertumpfelc {- at -} NIDDK {- dot -} NIH {- dot -} GOV
Date: 2008-02-27

Hi Donghui,
I just want to draw your attention to the following article. It sums up
suggestions which were already made by others for using concentrated
(lithium) salt solutions for cryoprotection:

Rubinson, K.; Ladner, J.; Tordova, M. & Gilliland, G. Cryosalts:
suppression of ice formation in macromolecular crystallography. Acta
Crystallogr D Biol Crystallogr, 2000, 56 ( Pt 8), 996-1001

Good luck,
christian

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. Christian Biertümpfel
Laboratory of Molecular Biology

NIDDK/National Institutes of Health phone: +1 301 402 4647
9000 Rockville Pike, Bldg. 5, Rm. B1-03 fax: +1 301 496 0201
Bethesda, MD 20892-0580
USA
_______________________________________________________________________

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CCP4bb <-- 2008 <-- February 2008 <-- 27 February 2008

Previous message:
Subject: Post doc position at Sussex University
From: Darren Thompson D {- dot -} Thompson {- at -} SUSSEX {- dot -} AC {- dot -} UK
Date: 2008-02-27