May I add the comment that despite the fact that it would be great if all of
the samples that I worked with would be stable at room temperature for 3 weeks,
if I had applied that as a criterion for crystallization screening and
subsequent structure determination, then my publication record
An excellent review on improving diffraction that has not been mentioned
yet is: https://doi.org/10.1107/S0907444905032130
As for how often it happens? At my beamline we do see this fairly
infrequently, but often enough that it no longer surprises me. I suppose
that brings some comfort to
Hi Careina
Expanding on what Tim says, try crushing your crystals to make a seed
stock, and adding it to a few *random screens - *preferably screens that
you have already tried with this target.
Search for instructions for MMS or rMMS online.
Good luck,
Patrick
On 14 August 2018 at 11:34,
Yes indeed!
Jon
--
Jon Hughes
(+49/0)1757929098
Sent without the use of Apple products.
Daniel M. Himmel, Ph. D. schrieb
Dear JL,
Years ago, this was a common problem when I was crystallizing myosin
constructs for my doctoral work. Some of the most beautiful crystals I
got showed
Dear JL,
Years ago, this was a common problem when I was crystallizing myosin
constructs for my doctoral work. Some of the most beautiful crystals I
got showed little or no diffraction. Often this occurs when there is a very
large water content in the asymmetric unit and in proteins that have a
Hi
Did you try them at room temp, in situ (straight in the plate). We
observe that time to time on our beamline, when just harvesting, not
mentioning cryo protection, is enough to loose all diffraction. It-s
rare but happens.
Regards
JL
On 14/08/2018 11:58, Careina Edgooms wrote:
I got
Hey Careina
I had once experience the same phenomenon. No diffraction at all. That did
not make any sense to me. So i dipped the "empty" loop in the water, and
flash froze the loop in liquid nitrogen. Once exposed to X-ray, there was
no ice rings... Eventually, it turned out that system had a
Hi Careina,
Some other things to check for:
Where did you measure the crystal, on a home source or at a synchrotron? if
at a synchrotron, try to put bit more flux and see whether you see any
diffraction?
Also check the beam and your crystal alignment.
Rangana
On Tue, Aug 14, 2018 at 12:15 PM,
Hi Careina,
if you don't have grey hair (available in the lab), you can still mount
crystals at room temperature. With a MiTeGen RT kit, very little skill is
required to test crystal diffraction or even collect entire data sets at
room temperature.
?We have some crystals that diffract well when fresh (less than one week old)
but lose almost all diffraction by the end of 2 weeks, so age can matter. One
crystals are in liquid nitrogen, they should be safe from further degradation,
but may suffer from ice contamination.
cheers, tom
Tom
Hi
One other thing to try that someone with grey hair in your lab might know about
- mount a "crystal" in a capillary and see if it diffracts at room temp. As
long as you have a source and detector in your home lab, there's no need to go
to a synchrotron and use their in situ facilities.
Dear Careina,
you could use the old crystals, that did not diffract, for microseeding
to regrew nicer crystals. Once you have them, try to use them as quickly
as possible. Three weeks can be a long time for crystals.
Storage in liquid nitrogen should not be the problem.
Best,
Tim
On
Yes, essential to test at room temperature without changing their buffer medium
before getting worried!
If they don’t diffract at RT, they are very very unlikely to diffract at
cryotemperatures, whatever you do to them before hand!
Best wishes
Elspeth
From: CCP4 bulletin board
Hello Careina,
Please send pics or didn't happen.
Anyway, in my very short experience, ugly crystals can diffract better than
beautiful ones. But have you checked first if they were protein crystals
or not?
Best of luck,
Nikk
On Tue, 14 Aug 2018, 11:59 Careina Edgooms, <
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