Re: [ccp4bb] Freezing under oil

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

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Subject: Re: Freezing under oil
From: Sabine Schneider sabine {- dot -} schneider {- at -} CUP {- dot -} UNI-MUENCHEN {- dot -} DE
Date: 2010-02-04

Hello Claudia,

Under what conditions did the crystals grow? If its sodium acetate and
ammonium sulphate I would try adding sodium malonate as a cryo
protectant (with 2-2.3M ammonium sulphate adding 0.6-0.8M Na malonate
should be sufficient) or increasing the ammonium sulphate concentration.

Sabine

Claudia Scotti wrote:
>
> Dear list,
>
> I'm trying to freeze crystals in cryoconditions containing the following:
>
> 0.1 M Sodium acetate pH 4.4
> 2.15-2.3 M Ammonium sulphate
> 7% n-butanol
> 15% glycerol
>
> The problem is that the crystals (beautiful hexagonal prisms) seem to
> shatter in a random fashion: some are unaffected, some, coming from
> the same drop, disgregate miserably. One even split into three parts,
> of which two disgregated and one survived perfectly well.
>
> I've tried both by moving the crystals directly in the cryocondition
> and by progressively increasing the glycerol concentration to no avail.
>
> Shall I just select those that survive?
>
> I was wondering if anybody has ever had this same problem and
> if freezing under oil could be an alternative. If yes: any suggestions
> on how to fish the crystals? I tried it in the past, but I found it
> very difficult...
>
> Experiences and suggestions are welcome.
>
> Claudia
>
>
>
>
>
> Claudia Scotti Dipartimento di Medicina Sperimentale Sezione di
> Patologia Generale Universita' di Pavia Piazza Botta, 10 27100 Pavia
> Italia Tel. 0039 0382 986335/8/1 Facs 0039 0382 303673
>
>
>
> Hotmail: Trusted email with powerful SPAM protection. Sign up now.
>

--
------------------------------------------
Dr. Sabine Schneider
Ludwig-Maximilians-University
Department of Chemistry
Butenandtstrasse 5-13, Building F
81377 Munich
Germany
Phone: +49 (0)89 2180 77752
Fax: +49 (0)89 2180 77756
http://www.carellgroup.de/

CCP4bb navigation

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

Previous message:
Subject: Re: Zalman LCD availability
From: Steffen Schmidt steffen {- dot -} schmidt {- at -} TUEBINGEN {- dot -} MPG {- dot -} DE
Date: 2010-02-04