Re: Freezing

[Harry Powell <harry@mrc-lmb.cam.ac.uk>]

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Just my two penn'orth...

Some macromolecule crystals (I've done it a lot with DNA oligos, and also
with lysozyme...) freeze well using the "oil-drop" method (remove crystal
from mother liquor, transfer to oil, remove surface moisture from crystal,
mount in loop); the best oil I found for this is, unfortunately, no longer
available commercially (it was Riedel-de Haen RS6000 polyfluoropolyether,
which had a nice sharp glass point at around -20C, IIRC). Much of the
damage caused during the freezing of many crystals is due to mother liquor
freezing on the surface of the crystal and pulling it apart, rather than
freezing in the solvent channels.

Harry 
-- 
Dr Harry Powell, MRC Laboratory of Molecular Biology, MRC Centre, Hills
Road, Cambridge, CB2 2QH