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:ar...@xtals.org]
Sent: Monday, October 05, 2009 9:05 PM
To: 'Tanner, John J.'; 'CCP4BB@JISCMAIL.AC.UK'
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:ccp...@jiscmail.ac.uk] On Behalf Of
Tanner, John J.
Sent: Monday, October 05, 2009 5:52 PM
To: CCP4BB@JISCMAIL.AC.UK
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
charles.b...@uwa.edu.au
+61 8 6488 4406
