I also wondered about the statement about oils blocking diffusion of O2. We had lots of trouble keeping things anaerobic in a glove box until we degassed the oils and waxes used to mount crystals in capillaries. We found that putting them under vacuum removed much of the dissolved oxygen. The waxes required cycling between heating and vacuum several times. Ron
On Wed, 18 Mar 2015, 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
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