If it's on a glass coverslip, another good trick is to (carefully) cut
through the skin around the crystal with a razor blade. With some
practice, one manages not to get the crystal entangled in the skin.
On Thu, 2010-11-25 at 16:03 +0000, Frederic VELLIEUX wrote:
> Hi,
>
> In our hands, the crystallisation droplets of glycosomal pyruvate
> phosphate dikinase had a 'skin' of what I thought was denatured
> protein at the surface of every crystallisation droplet. We had to
> learn to use the crystal microtools (such as a microknife, or a
> micro-needle can't remember what we have - sold by Hampton Research
> and I do not own shares in this company) to be able to cut this skin
> and drag it to the side of the droplet before being able to suck out
> the crystals. A bit like dissection under the binoculars.
>
> Fred.
>
> > Message du 25/11/10 15:56
> > De : "Rick"
> > A : [log in to unmask]
> > Copie à :
> > Objet : [ccp4bb] Tough 'shell' on disturbed drop
> >
> > 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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