Dear Enrico,
It is true that, on our beamline (FIP, at the ESRF), in situ (RT) is
mostly used for screening. But there is a fraction of cases where
freezing, and crystal handling, induces too much degradation. In these
cases, RT experiment is a real alternative.
In addition, data at room temp provide key information about the dynamic
(see Fraser et al., Accessing protein conformational ensembles using
room-temperature X-ray crystallography. PNAS, 2011, vol. 108,
16247-16252), which may be of great interest, specifically in a
structure based drug design approach.
regards
JL
On 02/06/2014 12:39 PM, Enrico Stura wrote:
Dear Joern and other BBers,
While I fully agree that it is important to test a few images at room
temperature, to know the crystal's
potential, I think that almost always it will be possible to achieve
better diffraction using cryogenic
data collection.
Those rare cases, as the one you mention below are worthy of critical
investigation as
to why there is a loss of order on cryo-cooling:
Unsuitable cryoprotectant is my first guess.
The rate of cooling in liquid N2 is slow, liquid ethane could be a
better choice.
Enrico
On Thu, 06 Feb 2014 11:19:47 +0100, Joern Krausze
<jk...@helmholtz-hzi.de> wrote:
Dear Theresa,
We recently collected a room temperature data set from one single
crystal at Petra III. The beam line was equipped with a Pilatus
detector. Data were good to 2.7 A. In contrast, at 100 K similar
crystals diffracted very poorly. So, it is perfectly possible to
obtain useful room temperature data sets from synchrotron sources. I
have to admit that in our case it certainly helped that the crystal
belonged to a high-symmetry space and full completeness was achieved
after 40 degrees angular range.
Regards,
Joern
Sent from my iPad
On 06.02.2014, at 10:51, Theresa Hsu <theresah...@live.com> wrote:
Dear crystallographers
Just out of curiosity, is it possible to collect datasets from
crystals at room temperature at synchrotron? Are fast detectors like
Pilatus useful for this?
Thank you.
Theresa
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