Re: [ccp4bb] Crystals grown from high ammonium sulphate

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

Previous message:
Subject: Crystals grown from high ammonium sulphate
From: Sabine Schneider sabine {- dot -} schneider {- at -} CUP {- dot -} UNI-MUENCHEN {- dot -} DE
Date: 2008-11-04

Next message:
Subject: Re: Crystals grown from high ammonium sulphate
From: Tim Gruene tg {- at -} SHELX {- dot -} UNI-AC {- dot -} GWDG {- dot -} DE
Date: 2008-11-04

Subject: Re: Crystals grown from high ammonium sulphate
From: Iain Kerr ikerr {- at -} CMP {- dot -} UCSF {- dot -} EDU
Date: 2008-11-04

Hi Sabine,

I had a similar problem years ago. Have you tried oils ? (mineral oil,
paraffin oil, 50:50 mixtures of either with N-paratone)

You can either 1. add a small amount (1ul or less) to the drop
containing the crystals and mount from there or 2. if you are quick
enough, transfer the crystal to a small drop of oil and mount it in the
cryostream straight from the oil.

HTH,
Iain

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/
>

CCP4bb navigation

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

Previous message:
Subject: Crystals grown from high ammonium sulphate
From: Sabine Schneider sabine {- dot -} schneider {- at -} CUP {- dot -} UNI-MUENCHEN {- dot -} DE
Date: 2008-11-04

Next message:
Subject: Re: Crystals grown from high ammonium sulphate
From: Tim Gruene tg {- at -} SHELX {- dot -} UNI-AC {- dot -} GWDG {- dot -} DE
Date: 2008-11-04