Stable Isotope Geochemistry


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Dr Tamsin O'Connell <[log in to unmask]>
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Stable Isotope Geochemistry <[log in to unmask]>
Thu, 21 Jul 2005 09:20:41 +0100
TEXT/PLAIN (65 lines)
Hi Diane,
I have done human blood both as a powder and as a liquid for EA-IRMS. You
can run it as a liquid if you pipette straight into the tin cap, fold over
and drop in. You could also put the tin cap + liquid into the bottom of a
microcentrifuge tube (the 0.5ml ones are good) and freezedry it before
running. You might need to experiment as to how much liquid you need to
pipette in, but it isn't much (fine for a 8x5mm cap if I remember right).
For running it as a powder, I freeze-dried it in a microcentrifuge tube
which made it into a solid 'lump' of powder if you know what I mean, then
I cut a small chunk off and put it in the tin cap. Blood powder was
certainly no worse than v fine collagen for getting everywhere, and at
least you could see it. A bottle of Virkon solution standing by is all you
need for a wipe-up.
But one thing to remember re biohazard protocols (well certainly in the
UK) is if yr blood is from low risk populations, the risk assessment needs
are different (less stringent) to those if yr blood is coming from a high
risk or unknown pop. My safety dept was v helpful in this regard.
I would be interested to know how you will handle it for TCEA though, as
how will you do the water equilibration?

Have fun!


On Wed, 20 Jul 2005, Diane O'Brien wrote:

> Hello All!
> 'm planning a project involving the analysis of human red blood cells
> via EA-IRMS and TCEA-IRMS.  Human blood is a biohazard because of the
> risk of HIV, hepatitis, etc.  There are CDC protocols for dealing with
> human blood safely as a liquid, but none that I've seen so far for
> powdered samples.  Powder has a knack for getting everywhere...  and is
> hard to weigh out in a biosafety hood!
> I'm trying some tests with non-human blood at the moment, including
> autoclaving it prior to freezedrying, to see how C, N, O and H ratios
> are affected.  Still, I know that isotopes are commonly used in medical
> studies and I'm sure I'm not the first person to confront this problem.
> Any leads?
> Cheers,
> Diane O'Brien
> _______________________
> Institute of Arctic Biology
> P.O. Box 757000
> University of Alaska
> Fairbanks, AK 99775-7000
> Office  (907) 474 - 5762
> Lab (907) 474 - 6093
> [log in to unmask]
Dr Tamsin O'Connell
McDonald Institute for Archaeological Research
University of Cambridge
Downing Street, Cambridge CB2 3ER, UK
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