Dear Sebastiano,
This is not entirely straight-forward.
The Oxford English dictionary gives the first definition of "freeze"
relevant to this discussion as:
"Of (a body of) water: be converted into or become covered with ice
through loss of heat"
This is certainly not what we want to do to our crystals.
However, another definition in OED is:
"Cause (a liquid) to solidify by removal of heat", suggesting that
this does not necessarily mean the formation of crystals.
The Larousse Dictionary of Science and Technology (1995) has the
following definition:
"Freeze-drying (Biol.) A method of fixing tissues sufficiently rapidly
as to inhibit the formation of ice-crystals."
The Dictionary of Microbiology and Molecular Biology (3rd Ed) in the
entry on "Freezing" has the sentence:
"Rapid freezing tends to prevent the ice crystal formation by
encouraging vitrification".
Both of these erstwhile volumes therefore suggest that freezing does
not necessarily imply the formation of crystals. However, the term is
ambiguous, while vitrification is not.
Personally I use "cryocooled" instead.
Best wishes,
Andrew
On 15 Nov 2012, at 17:13, Sebastiano Pasqualato 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?
Thanks a lot,
ciao,
s
--
Sebastiano Pasqualato, PhD
Crystallography Unit
Department of Experimental Oncology
European Institute of Oncology
IFOM-IEO Campus
via Adamello, 16
20139 - Milano
Italy
tel +39 02 9437 5167
fax +39 02 9437 5990
please note the change in email address!
sebastiano.pasqual...@ieo.eu
