Hi Carsten,
since you don't use them anymore I would volunteer to have them
shipped to me for free :-) I might cough up the shipping fee.
We have both in the lab, for certain purposes I prefer the stainless
steel over the foam dewars e.g. freezing protein as 20 µl drops then
picking them with tweezers and transferring them into an Eppendorf
tube. For use with the robotic equipment the stainless steel are
completely useless.
Ice formation can be prevented by exchanging the LN2 frequently.
Regarding the cane dewars out of foam as seen at ALS I don't like
them as they can be accidentally tipped over more easily than the
stainless steel dewars.
Jürgen
On 9 Oct 2008, at 06:15, Schubert, Carsten [PRDUS] wrote:
Hmmm, that's funny. Our experience was quite the opposite. The first
time we used one of the darker small dewars we ended up with a lot
of burr in the LN2. Those got picked up by the cryo and we ended up
with lilac particles embedded inside the cryo. You can imagine the
reaction when these particles showed up in the mounting camera ....
We also noticed that the LN2 in these dewars actually ices up more
rapidly as compared to the glass dewars. We attribute this to the
lower insulating capacity of the foam dewars, which causes a
vigorous boiling action and the higher turbulence seems to suck in
more ambient air. Needless to say the dewars did not make it past
the first use...
Carsten
-----Original Message-----
From: CCP4 bulletin board [mailto:[EMAIL PROTECTED] Behalf Of
[EMAIL PROTECTED]
Sent: Thursday, October 09, 2008 8:50 AM
To: CCP4BB@JISCMAIL.AC.UK
Subject: Re: [ccp4bb] foam dewar usage ?
Yes, we use them all the time and they're great. Stuff does not slip
on
the bottom like it does in the glass Dewars and the formation of ice
is
greatly reduced. Plus, they're much easier to dry.
Artem
Does anyone in the biocrystallogaphy community use foam dewars for
handly liquid nitrogen and freezing/manipulating frozen protein
crystals ?
-
Jürgen Bosch
University of Washington
Dept. of Biochemistry, K-426
1705 NE Pacific Street
Seattle, WA 98195
Box 357742
Phone: +1-206-616-4510
FAX: +1-206-685-7002
Web: http://faculty.washington.edu/jbosch
