Bones – Good cortical bone is best from the larger bones of the body (femur, tibia, upper arm bone, jaw, skull plate and sometimes the ribs).
Spongy bones like ball and sockets, vertebra, and the like do not tend to preserve well in harsh conditions and may not yield sufficient collagen for AMS dating.
Additional fee is charged for collagen or bone carbonate extraction.
The d13C and d15N ratios are measured using an isotope ratio mass spectrometer (IRMS).
The C: N, %C and %N results are much better indicators of good collagen.