Dear Andrea,
On Tue, Jul 12, 2016 at 01:03:57AM +0100, Andrea Thorn wrote:
> We are searching for a test case - perhaps you can help me out? We
> look for a data set measured on a pixel detector (Pilatus), where
> ice rings are so bad that phasing or refinement become difficult or
> impossible*.
> Please let me know if you could supply us with such a data set.
Some PDB entries you could try (based on publically available data,
like JCSG, SBGrid etc): 4PUC 4L8N 4JX0 5BYP 4KH9 4J8P 4KQT 5BXG
4R7F.
These are flagged up automatically as having ice-rings by our autoPROC
package (which then excludes those automatically) [1]. If you need
more I could look through our autoPROC logs a bit deeper.
If they give problems in phasing/refinement I don't know: I guess
without treating those ice-rings in a sensible way and depending on
what you do later on with that data, you could get into problems,
yes. We don't see that very often ourselves - but we do try and treat
them already at the earliest possible stage. Of course, not getting
ice-rings during cryo-cooling is the best approach ... ;-)
Cheers
Clemens
[1] http://www.globalphasing.com/autoproc/
http://www.globalphasing.com/autoproc/manual/autoPROC7.html#step1_spotnohkl
--
*--------------------------------------------------------------
* Clemens Vonrhein, Ph.D. vonrhein AT GlobalPhasing DOT com
* Global Phasing Ltd., Sheraton House, Castle Park
* Cambridge CB3 0AX, UK www.globalphasing.com
*--------------------------------------------------------------
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