>but for using osteocalcin which is tightly bound to the hydroxyapatite
>matrix and does not suffer from diagenetic effects that collagen may record.

>What is the verdict on this technique, is it useful or too laborious to
>analyze enough samples to be useful?

Later attempts to reproduce the techniques outlined in Ajie's early papers were
largely unsuccessful
and the osteocalcin/radiocarbon research evolved into attempts to isolate
gamma-carboxyglutamic
acid for C14 dating.  Results from that also proved rather uneven. See:

Burky, R.R., et. al.  (1998)  14C dating of bone using y-carboxyglutamic acid
and a-carboxyglycine
(aminomalonate)  RADIOCARBON, vol 40, no 1, p. 11-20.

I think the verdict is that the osteocalcin method is not useful, and the
general consensus in
radiocarbon dating is that dating collagen amino acids is the way to go.

   *************************************************
   Christine A. Prior, Ph.D.
   Rafter Radiocarbon Laboratory
   Institute of Geological & Nuclear Sciences
   [log in to unmask]     fax: +64 4 570-4657
   http://www.gns.cri.nz/atom/rafter/rafter.htm
   Society for Archaeological Sciences
   http://www.wisc.edu/larch/sas/sas.htm
   *************************************************