Re: [ccp4bb] Cryo-protectant

- Protein crystallography

Main steps:

- Protein purification
- Crystallisation

Special:

- Programs for crystallography
- X-ray detectors

Basic tutorials:

   - Chemistry
   - Protein
   - Peptide
   - Amino Acids

Xtal community:

- CCP4BB

CCP4bb navigation

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

Previous message:
Subject: Re: microbatch vs hanging drop
From: rui ruisher {- at -} GMAIL {- dot -} COM
Date: 2009-04-24

Next message:
Subject: Re: Reason for Neglected X-ray Fluorescence
From: Jacob Keller j-keller2 {- at -} MD {- dot -} NORTHWESTERN {- dot -} EDU
Date: 2009-04-24

Subject: Re: Cryo-protectant
From: Joe gchen2 {- at -} GMAIL {- dot -} COM
Date: 2009-04-24

First of all, you need to find out if crystals you grew have similar
quality before you conclude poor diffraction is due to cryoprotectant
solutions. As others have suggested, you can test crystals using
capillary mounting method. Second, there are a lot more cryoprotectant
agents out there you can try. Not sure why you sticked to MPD, which is
not even present in your crystallization condition.

One of protein crystallized in almost the same condition as yours. What
I did is just simply increasing % PEG3350, in addition to 10%-15%
increment of every other ingredients (your protein buffer + well
solution). I also introduced 5% glycerol to bring down % PEG3350. You
can play around % PEG3350 and % glycerol to find a fine combination
that is cryo-clear and makes you crystals happy.

Joe

Liew Chong Wai wrote:
cite="mid:48BABA4E8A54DF4AAF9CCF36D6140273040B2B7F@EXCHANGE23.staff.main.ntu.edu.sg"
type="cite">
Re: [ccp4bb] Cryo-protectant

Hi all

Thanks for your
precious suggestions and ideas.

The crystallization buffer
condition is 0.1M BIS-TRIS pH 5.5, 0.2M MgCl.6H2O, 35% PEG3350

Now, my crystal seem ok in
20% ethylene glycol, but only after a couple minutes of dehydration at
room temperature. For sure, i will try other cryoprotectant that was
suggested here.

I just wondering why MPD
kills the crystal.

Many thanks

face="Arial" size="2">

LIEW

CCP4bb navigation

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

Previous message:
Subject: Re: microbatch vs hanging drop
From: rui ruisher {- at -} GMAIL {- dot -} COM
Date: 2009-04-24

Next message:
Subject: Re: Reason for Neglected X-ray Fluorescence
From: Jacob Keller j-keller2 {- at -} MD {- dot -} NORTHWESTERN {- dot -} EDU
Date: 2009-04-24