Hi Ed,
good question. I have found that you have a good 30 seconds to remove
the surrounding liquid - so while you have to do it fast you have enough
time that it doesn't need a robot and even a malcoordinate such as
myself can do it. I'm afraid that I have no estimate for how often
diffraction is lost this way.... more info here
http://scripts.iucr.org/cgi-bin/paper?S0907444911031210
I started looking at this when doing dehydration experiments where it
has long been observed that you can directly cool the crystals after
dehydration - I have a feeling that 'over drying' a crystal leads to a
complete loss of lattice order - I have no evidence for this but all
systems that we have looked at that benefit from dehydration, or not,
come to quite a sharp cutoff where suddenly there is no more
diffraction, one can often recover diffraction by rehydration. This
could of course be due to too high a concentration of mother liquor but
quite often it occurs at relative humidity values Cheers, Matt.
On 2013-05-23 15:32, Ed Pozharski wrote:
> Matt,
>
> with this technique, how do you prevent crystal from drying up (other
> than "doing it fast")? I know Thorne's group does this trick under
> oil.
> If you take no extra precautions, do you have an estimate of how
> often
> diffraction is destroyed by this?
>
> On the other hand, it's quite possible that what destroys resolution
> when crystals dry up is increase in concentration of non-volatile
> mother
> liquor components, which shouldn't be happening here to the same
> degree.
>
> Cheers,
>
> Ed.
>
> On Thu, 2013-05-23 at 14:38 +0200, Matthew BOWLER wrote:
>> Hi Faisal,
>> if your solvent channels are smaller than 40A in the largest
>> dimension
>> (most are) you can use a mesh loop to pick up the crystal and then
>> wick
>> away all of the mother liquor. You can then flash cool your crystal
>> without having to transfer the crystal to another solution. Good
>> luck,
>> Matt
--
Matthew Bowler
Synchrotron Science Group
European Molecular Biology Laboratory
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38042 Grenoble Cedex 9
France
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