Re: [ccp4bb] Crystals grown from high ammonium sulphate

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CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

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Subject: Re: tricoordinated ion?
From: "Borhani, David" David {- dot -} Borhani {- at -} DESHAWRESEARCH {- dot -} COM
Date: 2008-11-04

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Subject: Re: Crystals grown from high ammonium sulphate
From: Savvas Savvides savvas {- dot -} savvides {- at -} UGENT {- dot -} BE
Date: 2008-11-04

Subject: Re: Crystals grown from high ammonium sulphate
From: shiliang shiliang {- at -} MOON {- dot -} IBP {- dot -} AC {- dot -} CN
Date: 2008-11-04

You can try microseeding. It is really suitable for crystallization in high
ammonium sulphate. I got a similar problem as well, before. Microseeding can
supply nucleus. You can get more crystals and spend less time.

And for the salt crystallization, I think if you transfer quickly it can be
fine. Or a high humidity might be useful.

Liang

On Tue, 4 Nov 2008 19:34:20 +0100, Sabine Schneider wrote
> Hi everyone,
>
> We got crystals that grew in ~3.2M ammonium sulphate and some
> tris-buffer at 18dgC. Unfortunately the crystals take a while to grow
> (~4-5 weeks) and so far we only have 4-5 xtals. I tried to freeze
> the crystals, but as soon as I broke though the skin of the drop the
> ammonium sulphate started to crystallise. I got the crystals out,
> froze them using sort of an artifical mother liquor with sodium
> malonate as cryo and tested the diffraction. The freezing seems to
> be OK and it is definitely a protein crystal. The crystal suffered
> when the ammonium sulphate in the drop started to crystallise, but
> didn't seem to deteriorate anymore in the cryo. Well the corners had
> already more or less disappeared by the time I got them out of the drop...
> Since we only have a few xtals at the moment and I can't try out a
> lot of things, I was wondering if anyone has experienced and solved
> a similar problem? My freezing attempt so far was in an
> airconditioned room with 18dgC. I thought about higher humidity and
> temperature in the room, and/or adding the cryo directly to the
> drop.... Any ideas are very much appreciated!
>
> Sabine
>
> ------------------------------------------
> Dr. Sabine Schneider
> Ludwig-Maximilians-University
> Department of Chemistry and Pharmacy
> Butenandtstrasse 5-13, Building F
> 81377 Munich
> Germany
> Phone: +49 (0)89 2180 77846
> Fax: +49 (0)89 2180 77756
> http://www.carellgroup.de/

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CCP4bb navigation

CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: Re: tricoordinated ion?
From: "Borhani, David" David {- dot -} Borhani {- at -} DESHAWRESEARCH {- dot -} COM
Date: 2008-11-04

Next message:
Subject: Re: Crystals grown from high ammonium sulphate
From: Savvas Savvides savvas {- dot -} savvides {- at -} UGENT {- dot -} BE
Date: 2008-11-04