Re: CO2 grade for on-scope incubator?

Posted by Craig Brideau on
URL: http://confocal-microscopy-list.275.s1.nabble.com/CO2-grade-for-on-scope-incubator-tp7582397p7582410.html

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I agree that special CO is unnecessary. As Kurt says, the atmospheric water
is probably higher anyway. The one thing we have done in the past is swap
out carbogen (5% CO2 balance O2) for a 5% CO2 balance air mixture, because
we found 95% O2 was harsh on a particular sample.

Craig Brideau


On Tue, Jul 22, 2014 at 6:30 PM, Loralei Dewe <[hidden email]> wrote:

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>
> It seems to me that if this is a problem use the culture medium that has
> phenol red so you can see the pH change occuring.   In all my years, I've
> never had to order specific CO for microscopy.
>
> Loralei
>  On Jul 22, 2014 4:45 PM, "Peter Werner" <[hidden email]> wrote:
>
> > *****
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> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
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> posting.
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> >
> > At our facility, we have a spinning-disk confocal system, with an
> > incubator that surrounds the entire stage and substage area. The
> question I
> > have concerns the type of CO2 I should be using for the incubator. I was
> > told by someone from the UC Berkeley Biological Imaging Facility that I
> > should be careful about the grade of carbon dioxide that I use -
> > apparently, it should be high purity and as low as possible in H2O. The
> > reason is, even if the cell cultures themselves will be fine with a lower
> > purity of CO2, CO2 forms carbonic acid in reaction with water, and the
> > acidified water content in the chamber atmosphere can be damaging to the
> > instrument over the long term, hence, the less H2O mixed in with the CO2,
> > the better. If this is the case, that would imply that "Instrument Grade"
> > or "Bone Dry" grades would be what I need to use.
> >
> > I was wondering if anybody else knew of this recommendation and followed
> > this practice. It makes sense to me why one would want to minimize
> carbonic
> > acid formation in environments the confocal system is exposed to. On the
> > other hand, it does entail some expense, not so much in terms of the gas
> > itself, but in terms of special cylinders for high-purity CO2, which must
> > be rented, or purchased at $500+ per gas cylinder.
> >
> > Let me know,
> > Peter G. Werner
> > Instructional Assistant/Lab Technician, Microscopy, Merritt College
> > SEM/AFM Lab Technician, Ohlone College
> > [hidden email]
> >
>