Hi,
As far as I can tell oil does not block diffusion of O2 whatsoever. You
can keep larger volumes (≥1 ml) of solutions anoxic in air for several
hours with dithionite (≥0.5%) to scavenge oxygen and a redox indicator
dye such as phenosafranin to monitor the state of the solution. Small
drops (large surface/volume ratio) however oxidize within seconds,
whether or not they are covered with oil. Of course this may simply be
because the oxygen gets in before the drop is covered with oil, but
either way I don't see how you could set up anaerobic drops in an
aerobic environment.
Best,
Julia
On 18/03/15 14:47, Edward A. Berry wrote:
Do you have evidence that the oil blocks diffusion of O2? O2 is a
nonpolar molecule, generally much more soluble in oils than in water.
I'm not sure about silicone oils, but I would think they also dissolve
O2 readily.
eab
On 03/18/2015 08:02 AM, Patrick Shaw Stewart wrote:
Hi Steve
I have one more comment for this thread.
The microbatch-under-oil method is very handy for anaerobic work:
1. You can keep the microbatch stock solutions in normal
microtitre plates (polypropylene is best to reduce evaporation) for
months, which hugely reduces the amount of degassing that you need to
do. You will only use say 0.5 ul of stock per drop.
2. The oil offers a surprising amount of protection from
oxidation, which may be helpful eg in harvesting.
3. Microbatch can be automated - in parallel to vapor diffusion
if desired
It's amazing how often (aerobic) microbatch produces far superior
crystals to V.D. for no obvious reason - it's well worth trying for
both screening and optimization.
Best wishes
Patrick
On 11 March 2015 at 10:17, <Stephen Carr>
<[email protected]
<mailto:[email protected]>> wrote:
Dear CCP4BBer's
Apologies for the off-topic post, but the CCP4BB seems to be the
best place to ask about crystallisation.
I am looking to set up crystallisation in an anaerobic glove box
and wondered how other people did this, specifically the
crystallisation stage. My initial thoughts were to place a small
crystallisation incubator inside the box, however the smallest I have
come across so far (~27L) is still rather large. Has anyone come
across smaller incubators? Alternatively are incubators even
neccessary if the glove box is placed in a room with good air
conditioning and stable temperature control?
Any recommendations would be very helpful.
Thanks in advance,
Steve Carr
Dr Stephen Carr
Research Complex at Harwell (RCaH)
Rutherford Appleton Laboratory
Harwell Oxford
Didcot
Oxon OX11 0FA
United Kingdom
Email [email protected]
<mailto:[email protected]>
tel 01235 567717 <tel:01235%20567717>
This email and any attachments may contain confidential,
copyright and or privileged material, and are for the use of the
intended addressee only. If you are not the intended addressee or an
authorized recipient of the addressee, please notify us of receipt by
returning the e-mail and do not use, copy, retain, distribute or
disclose the information in or attached to this email.
Any views or opinions presented are solely those of the author
and do not necessarily represent those of the Research Complex at
Harwell.
There is no guarantee that this email or any attachments are free
from viruses and we cannot accept liability for any damage which you
may sustain as a result of software viruses which may be transmitted
in or with the message.
We use an electronic filing system. Please send electronic
versions of documents, unless paper is specifically requested.
This email may have a protective marking, for an explanation,
please see:
http://www.mrc.ac.uk/About/informationandstandards/documentmarking/index.htm.
--
[email protected] <mailto:[email protected]> Douglas
Instruments Ltd.
Douglas House, East Garston, Hungerford, Berkshire, RG17 7HD, UK
Directors: Peter Baldock, Patrick Shaw Stewart
http://www.douglas.co.uk
Tel: 44 (0) 148-864-9090 US toll-free 1-877-225-2034
Regd. England 2177994, VAT Reg. GB 480 7371 36
--
Dr. Julia Griese
Postdoctoral Researcher
Stockholm Center for Biomembrane Research
Department of Biochemistry and Biophysics
Stockholm University
106 91 Stockholm
Sweden
phone: +46-(0)8-162 778
email: [email protected]
