On Mon, 07 Jan 2013 18:30:32 +0100, Joy <joybeiy...@gmail.com> wrote:
Dear Bryan,
Thank you very much for the comments, I have tried glycerol and it did
affect the resolution, at the same time, through reading former posts, I
find that sucrose might not be a good choice for crystals grown in salt,
I will definitely try adding glycerol stepwise, but at the same time,
Glycerol is a solubilizer. A step wise approach will work only if as you
increase the glycerol concentration you also increase the precipitant
concentration. Be careful of salt crystals appearing as you take this path.
I am wondering if high conc. ammonium phosphate could be used as
cryoprotectant, if so, I would be able to achieve dehydration and cryo
at the same time.
All salts will prevent ice formation at high concentration, but some reach
the crystallization point
before. There is also the possibility of making a salt mixture by adding
for example
ammonium formate, an excellent cryosalt.
If you try the experiment and let the BB know the result.
Enrico.
From: Prince, D Bryan [mailto:dbryan.pri...@astrazeneca.com]
Sent: 2013年1月3日 17:17
To: Joy
Subject: RE: [ccp4bb] Ammonium phosphate as cryoprotectant
Dear Joy,
I do not believe that ammonium dibasic phosphate will make a good
cryosalt. I would recommend a lithium cryosalt (formate, acetate or
sulfate) or glycerol if you really need to stay with the phosphate.
Hope this helps!
Bryan
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From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Joy
Sent: Thursday, January 03, 2013 12:33 PM
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] Ammonium phosphate as cryoprotectant
Dear All,
May I have your expert opinion on the following question: what is the
minimum concentration of ammonium dibasic phosphate if I would like to
use it as cryoprotectant?
Happy New Year!
Joy
--
Enrico A. Stura D.Phil. (Oxon) , Tel: 33 (0)1 69 08 4302 Office
Room 19, Bat.152, Tel: 33 (0)1 69 08 9449 Lab
LTMB, SIMOPRO, IBiTec-S, CE Saclay, 91191 Gif-sur-Yvette, FRANCE
http://www-dsv.cea.fr/en/institutes/institute-of-biology-and-technology-saclay-ibitec-s/unites-de-recherche/department-of-molecular-engineering-of-proteins-simopro/molecular-toxinology-and-biotechnology-laboratory-ltmb/crystallogenesis-e.-stura
http://www.chem.gla.ac.uk/protein/mirror/stura/index2.html
e-mail: est...@cea.fr Fax: 33 (0)1 69 08 90 71
