On Thursday, November 15, 2012 09:13:58 am you wrote:
>
> Hi folks,
> I have recently received a comment on a paper, in which referee #1 (excellent
> referee, btw!) commented like this:
>
> "crystals were vitrified rather than frozen."
>
> These were crystals grew in ca. 2.5 M sodium malonate, directly dip in liquid
> nitrogen prior to data collection at 100 K.
> We stated in the methods section that crystals were "frozen in liquid
> nitrogen", as I always did.
>
> After a little googling it looks like I've always been wrong, and what we are
> always doing is doing is actually vitrifying the crystals.
> Should I always use this statement, from now on, or are there english/physics
> subtleties that I'm not grasping?
What we aim for is vitrification: "to make into a glass".
What we achieve is another matter.
Sometimes dipping into LN2 produces a partially ordered (non-glasslike)
state in the solvent that is bad for our diffraction experiment.
Either result, the desired glass or the unfortunately crystalline ice,
is an example of freezing: "to make into a solid by removing heat".
Ethan
--
Ethan A Merritt
Biomolecular Structure Center, K-428 Health Sciences Bldg
University of Washington, Seattle 98195-7742
