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 : CCP4BB@JISCMAIL.AC.UK > > 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
