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Useful summary, Artem. Two comments spring to mind. - I have had trouble with slight bending of needles when frozen like this, causing problems with mosaicity. (Presumably due to different forces acting on the parts of the crystal within and without the loop.) - You can have lots of trouble measuring systematic absences in crystals mounted like this as the unique axis in hexagonal or tetragonal is close to the rotation axis. Cheers, Charlie Artem Evdokimov wrote: > Sorry, hit send by accident. Here it is: > > http://www.xtals.org/pdfs/needles.pdf > > Artem > > -----Original Message----- > From: Artem Evdokimov [mailto:[log in to unmask]] > Sent: Monday, October 05, 2009 9:05 PM > To: 'Tanner, John J.'; [log in to unmask] > Subject: RE: [ccp4bb] Mounting needle-shaped crystals > > Hello felow MO crystallographer, > > For all it's worth, a while ago I've compiled a little document which > describes mounting needles. I've converted it into PDF and posted it here: > > > "Nothing is built on stone; all is built on sand, but we must build as if > the sand were stone" > Jorge Luis Borges > > > -----Original Message----- > From: CCP4 bulletin board [mailto:[log in to unmask]] On Behalf Of > Tanner, John J. > Sent: Monday, October 05, 2009 5:52 PM > To: [log in to unmask] > Subject: [ccp4bb] Mounting needle-shaped crystals > > Dear CCP4, > > I'm looking for advice on mounting thin needles for low temperature data > collection. Our needles are fairly long (100-200 microns) but only 20 > microns or less thick. When I pick them up with Hampton loops (0.05-0.1 mm > size), the crystals tend to break as they are moved out of the drop and > through the liquid-air interface. > > I see that Mitegen sells MicroLoops E, which are advertised as working well > for mounting needles. Can anyone recommend them? Can anyone recommend > Mitegen MicroMeshes or another tool for mounting needles? > > Thanks, > > Jack Tanner > > -- Charlie Bond Professorial Fellow University of Western Australia School of Biomedical, Biomolecular and Chemical Sciences M310 35 Stirling Highway Crawley WA 6009 Australia [log in to unmask] +61 8 6488 4406