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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> >> <[log in to unmask] >> <mailto:[log in to unmask]>> 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 [log in to unmask] >> <mailto:[log in to unmask]> >> 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. >> >> >> >> >> -- >> [log in to unmask] <mailto:[log in to unmask]> 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: [log in to unmask]