The shell may be denatured protein. Remove the protein from the
experiment and the problem will likely go away.
On 11/25/10 09:45, Rick wrote:
Dear CCP4
I looped a v.thin rod emerging from a cluster of v.thin rods that grew in
29%PEG1500 and 0.1M SPG buffer at pH7.5 (succinic acid, sodium dihydrogen
orthophospate and glycine). The loop i used had been washed more than 10 times
with deionised water (so assumed as 'clean'). The crystals had grown at
17degreesC, and looped out probably just below room temperature (~20-23
degreesC). When transferred to 5% glycerol cryo-buffer the crystal
disintegrated (maybe due to glycerol being an unfavourable addition to the
mother-liquor). When i looked back at the original cluster-containing drop, a
very tough shell had formed over the surface of the drop, from which chunks
could be dug out...the nearest analogy is maybe like when you blow-torch sugar
on top of creme brulee, and have to crack it with your spoon. The crystals
within had also disintegrated. Any clues to what might have caused this very
tough shell to form, and maybe how to deal with it?
Much appreciated
Rick Salmon
--
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All Things Serve the Beam
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David J. Schuller
modern man in a post-modern world
MacCHESS, Cornell University
schul...@cornell.edu
