Re: [ccp4bb] crystallisation

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From: Gerard DVD Kleywegt gerard {- at -} XRAY {- dot -} BMC {- dot -} UU {- dot -} SE
Date: 2008-06-03

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Subject: Re: crystallisation
From: Clemens Vonrhein vonrhein {- at -} GLOBALPHASING {- dot -} COM
Date: 2008-06-03

Subject: Re: crystallisation
From: Christian Biertuempfel biertumpfelc {- at -} NIDDK {- dot -} NIH {- dot -} GOV
Date: 2008-06-03

Hi Sajid,
Just a simple test for your problem: Incubate your crystal longer in
your cryo/stabilization solution. This helps sometimes to lower
mosaicity. Of course, you can also try co-crystallization with glycerol
(2%, 5% or 10%).

Good Luck,
christian

sajid akthar wrote:
> Dear All
>
> My protein size is ~30kD and crystallizes with
> 19%Peg3350, 0.2M Nacl, and 0.1M Na Cacodylate buffer.
>
> Please refer the attached crystal image with this. The
> crystal looks like good enough for home source. These
> crystals appears in 4-5 days at room temp.
>
> Sometimes I'm getting crystals like this, but very few
> in 24 well tray. Most of the time, I found the drop
> contains needles. If I reduce the precipitant little
> bit, I wont find any change in the drop even after
> long time. Changing pH (or temp)of the buffer does not
> help me any better. The crystal appears only around
> 5.5pH.
>
> The problem is mosaicity. This crystal diffracted in
> home source upto 3.2A and the mosaicity is 2.5degree.
> Almost all the good crystal like this having same
> mosaicity.
>
> Good cryo condition so far that I found was
> 10%Glycerol with mother liquor. Other conditions
> weekens the diffraction quality or increase mosaicity.
>
> In many crystal I could see some crack in the middle
> of the crystal, it looks like twin crystal. Or the
> crystal appears with some sattelite crystals.
>
> Can anyone suggest me some good way to overcome these
> problems.
>
> Thankz
>
> Sajid
>
>
>
> From Chandigarh to Chennai - find friends all over India. Go to http://in.promos.yahoo.com/groups/citygroups/
>
>
> ------------------------------------------------------------------------
>

_______________________________________________________________________

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 <-- June 2008 <-- 03 June 2008

Previous message:
Subject: Re: Multimer threading server
From: Gerard DVD Kleywegt gerard {- at -} XRAY {- dot -} BMC {- dot -} UU {- dot -} SE
Date: 2008-06-03

Next message:
Subject: Re: crystallisation
From: Clemens Vonrhein vonrhein {- at -} GLOBALPHASING {- dot -} COM
Date: 2008-06-03