Search Results

Osteomark NTx Point of Care (POC) is a urinary assay for the quantitative measure of the excretion of cross-linked N-telopeptides of type I collagen (NTx) normalized to urinary creatinine (nM Bone Collagen Equivalents/mM creatinine). The test is used to monitor bone resorption changes following initiation of antiresorptive therapy (e.g., hormone replacement therapy).

The Osteomark® NTx POC device is a single-use, disposable four-channel reflectance photometer integrated with dry reagent chemistry strips and contained within a sealed plastic case. Each unit consists of: - an optics subassembly that also supports the reagent strips . - electronics, batteries, photodetectors, and light emitting diodes (LEDs). ● - . plastic parts - two reagent strips ● - a desiccant ● - a liquid crystal display (LCD) ● The reagent strips capillary transport with various chemical reactions. The first strip is an immunoassay for measuring the NTx, and the second strip is a general chemistry assay for measuring the creatinine. In both strips, a blue color is measured in discrete test zones. The test zones are the areas where the specific reaction occurs and concentrations are measured. The NTx reaction proceeds as follows: anti-NTx antibody, conjugated to blue microparticles, migrate across the strip upon the addition of urine sample. The amount of blue microparticles captured on the test zones is proportional to the amount of NTx in the sample. The creatinine reaction proceeds as follows: the addition of the urine sample solubilizes enzymes immobilized in the strip test zones. A cascade of enzymatic reactions mediates the production of hydrogen peroxide from the oxidation of creatinine. In the presence of horseradish peroxidase and a color indicator, a blue color is generated from the hydrogen peroxide with an intensity proportional to the concentration of creatinine in the sample. The LEDs and silicon photodetectors compare the reflectances of the color intensities before and after the sample addition. Based on the calibration parameters stored in memory, the numerical concentrations of NTx and creatinine are calculated. Assay results are expressed in nM Bone Collagen Equivalents (BCE) divided by mM creatinine (nM BCE/mM creatinine).