Bone metabolism

Product name

PYD Serum (Quidel®)

Pyridinoline Crosslinks

Free PYD is measured

Range0.75 - 12 nmol/l
Sensitivity0.4 nmol/l
Incubation time26 hours
Sample volume200 µl
Sample type


Sample preparation

Keep specimens at 2-8°C for a maximum of 4 days or at -20°C for longer storage. No more than 3 freeze/thaw cycles. Filter samples by adding 200 µl to a 30kMWCO Spin filter. Centrifuge 30 minutes at 3,000-10,000 x g. Protect filtrate from exposure to light.

Reference values
  (nmol/l) S.D. (nmol/l)
Premenopausal women (25 - 44 years) 1.55 0.26
 Men (25 - 55 years) 1.59 0.38

Reference values from children are available.


Human, baboon, cat, bovine, dog, guinea pig, horse, rhesus macaque, mouse, rat, sheep

Cross reaction

No cross reaction with free DPD, < 2.5 % with PYD/ DPD peptides

Tests96 Tests
Intended use

When bone or cartilage collagen is degraded, PYD is released into circulation and excreted in the urine. Deoxypyridinoline (DPD), a pyridinium crosslink differing from PYD only by the absence of an hydroxyl group, is essentially bone specific. The ratio of PYD:DPD in bone of approximately 4:1 is closely concordant with the ratio observed in urine of healthy individuals and those with metabolic bone diseases or osteoarthritis in spite of a much higher PYD:DPD ratio in non-bone tissues. In rheumatoid arthritis, destruction of cartilage and other collagen-containing joint tissue may contribute to increased levels of PYD.
Pyridinoline crosslinks are indicators for type-I collagen resorption, particularly for bone collagen.

Product informations

Back to overview