The Osteomark® NTx-Serum test is used for the quantitative measurement of cross-linked N-telopeptides of type I collagen in serum. The NTx molecule is bone-specific due to the unique amino acid sequences of the cross-linked alpha-2 (I) N- telopeptide. Release of the NTx molecule is mediated by osteoclasts. Elevated levels of NTx indicate elevated bone resorption.

Serum NTX-levels are used for:

  • monitoring of antiresorptive therapy in individuals diagnosed with osteoporosis
  • predicting response to hormonal antiresorptive therapy in postmenopausal women

Quick Facts

  • Range: 5-40 nM BCE
  • Sensitivity: 3.2nM BCE
  • Incubation time: 2 hours
  • Sample volume: 2x 100µl (pre-diluted 1:5 with Specimen Diluent)
  • Sample type: serum, cell culture

Species: human, bovine, sheep, porcine, rabbit, rat, and rhesus macaque

Human serum is collected by standard venipuncture technique. Store samples refrigerated at 2-8°C for up to 24 hours or frozen at -20 °C for longer storage. Stable up to 3 freeze and thaw cycles.

For monitoring therapy, baseline samples should be collected just prior to or on the day of therapy initiation. Subsequent specimens for comparison should be collected at approximately the same time of day as the baseline specimen.

nmol Bone Collagen Equivalents/l (nM BCE)

Mean Range (± 2 SD)
Premenopausal women (25 – 49 yrs) 12.6 6.2 – 19.0
Men (31 – 80 yrs) 14.8 5.4 – 24.2