Thanks for all the input. I'll try to respond to some of the points made.
Kelly - the dewar is quite narrow in diameter so there's little space to
maneuver, the puck fits snugly. Unfortunately we are limited by the
size of the port so we can't use a larger one. Additionally the dewar
sits below the level of the bottom of the box and so reaching down to
the vial with much control is tricky.
Kris - I like the idea of saving directly into the vial, however to do
so would require access to the dewar with two hands! At the moment with
the microscope position this isn't possible. The cryo has been pretty
well optimised over several years and works well aerobically. But for
your info contains:
Matthew - see above, issues with one-handed freezing! Also we're going
to try to manufacture a 'half-puck' holder for vials. This will
hopefully give us some space to work.
Bryan - where to start...
We'd hope to avoid further modifying the glovebox although it's becoming
apparent that rearranging the microscope set to move the pillar out of
the way would make a lot of sense. Further to the diagram on the Belle
website our box has been modified to have a 2nd LN2 dewar port to the
right of the microscope - still issues with one handed access at this
point (left handed practice not required).
Nian - The humidity in the box is only 8 % which is why the formation of
ice is somewhat puzzling - possibly it is occuring after the glovebox
during subsequent trasnfer to canes etc. We may try an in-line moisture
scrubber to remove the last
Peter - good luck!
Patrick - the dewar port has a nitrogen purge across the top of it,
which we have been leaving on during the freezing process. This sounds
as if it should do what you're describing. Will have a look at those
papers, thaknks!
Cheers,
Dave
On 24/04/2012 15:52, Kelly Daughtry wrote:
Is there room in the LN2 to plunge directly in, then maneuver into
puck? That's what I did, with a different setup, but still anaerobic
and moving into pucks. I did not run into ice problems. If there is
not room within the LN2 bowl, can you use a larger one?
I've found any hesitation when heading into LN2 (i.e.increased time
spent hovering over LN2 in the gas/semi cool area) can cause ice. Thus
I always try to plunge in quickly, then maneuver to the
desired storage location (puck, cap).
Kelly
*******************************************************
Kelly Daughtry, Ph.D.
Post-Doctoral Fellow, Raetz Lab
Biochemistry Department
Duke University
Alex H. Sands, Jr. Building
303 Research Drive
RM 250
Durham, NC 27710
P: 919-684-5178
*******************************************************
On Tue, Apr 24, 2012 at 10:20 AM, David Gallagher
<dt...@mrc-mbu.cam.ac.uk <mailto:dt...@mrc-mbu.cam.ac.uk>> wrote:
Hi all,
I've been using a Belle technologies anaerobic glovebox with in
built microscope and liquid nitrogen dewar port in an attempt to
harvest and cryo-cool crystals in an oxygen free environment.
I've been having some problems with icing and think this is most
likely due to slow speed that it is possible to plunge loops into
the liquid nitrogen. I've been plunging loops straight into vials
preloaded into an ESRF puck (with pusher). This requires more
care than what I would ordinarily do (i.e. plunging into bulk
liquid nitrogen then and manouvering into a vial afterwards and
then clipping said vial into a cane) and so takes longer - perhaps
leading to icing. The latter technique is not available as the
glovebox set up means that the dewar can only be reached by my
right hand - the microscope is in the way!
Does anyone have any experience of a similar set up and if so have
some advice as to how I can overcome this problem?
Many thanks,
Dave Gallagher
--
*David Gallagher *
PhD Student
MRC Mitochondrial Biology Unit
Wellcome Trust / MRC Building
Hills Road
Cambridge
CB2 0XY
Email: dt...@mrc-mbu.cam.ac.uk <mailto:dt...@mrc-mbu.cam.ac.uk>
Phone: 01223 252913
--
*David Gallagher *
PhD Student
Bacterial Complex I Group
MRC Mitochondrial Biology Unit
Wellcome Trust / MRC Building
Hills Road
Cambridge
CB2 0XY
Email: dt...@mrc-mbu.cam.ac.uk <mailto:dt...@mrc-mbu.cam.ac.uk>
Phone: 01223 252913
