When I have demineralised teeth, I have cracked them to clean them, then
demineralised the chunks of tooth. The form of insoluble residue which is
left depends upon the preservation of the teeth. I have been left with
material that is like small shreds, and I have seen residue that forms a
soft nugget until dried.
If there is poor preservation, you may be left with shreds which you will
see most clearly when they are suspended in your demineralising solution -
but collecting them from a filter paper after filtering/rinsing would be
When I do CN analysis on bone and teeth, I use gelatin extracted from this
residue (the "collagen").
Because I gelatinise the residue after demineralisation, I do the
following: pre-weigh a glass fibre filter paper used in the filtering
apparatus: filter onto this, then dry and re-weigh. The dried filter with
the fine residue is then used in a weak acid solution under vacuum and
heat to extract "gelatin". By freeze drying this and reconstituting it to
a known concentration, you can accurately measure the wt of the material
submitted for CN.
If you are interested in this method, email me at [log in to unmask] and
I will discuss this with you further.
Dr. Nancy Beavan Athfield
Rafter Radiocarbon Laboratory
Geological and Nuclear Sciences
PO Box 31 312, Gracefield, Lower Hutt
DD 64 4 570 4650
FAX 64 4 570 4657
Jenny O <[log in to unmask]>
Sent by: Stable Isotope Geochemistry <[log in to unmask]>
Please respond to Stable Isotope Geochemistry
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Subject: Collagen Extraction in Teeth
I am an undergraduate student working on a small project in which I
extract collagen from bones and teeth in order to perform isotopic
analysis. I am having trouble determining whether or not some of the teeth
that I am working on are demineralized. I am treating them with 0.3 M HCl.
know that bones are demineralized when they appear to be spongy, or
completely soft. Is that true with teeth? I am also worried that I could
demineralizing too long (is that possible?).
Thanks for your time,
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