• Derived exclusively from bone-resorbing osteoclasts
  • Low diurnal variation
  • No dietary influence
  • No accumulation into the circulation in renal or hepatic failure

For the quantitative determination of the active isoform 5b of tartrate-resistant acid phosphatase (TRACP). The BoneTRAP® (TRAcP 5b) ELISA assay is a specific method to detect TRACP 5b activity freshly liberated from osteoclasts. It is intended for use as an indicator of bone resorption and can be used as an aid in monitoring bone resorption changes in post-menopausal women and individuals diagnosed with osteoporosis undergoing anti-resorptive therapies.

In-vitro, TRACP 5b activity reflects the number of osteoclasts and therefore the BoneTRAP® (TRAcP 5b) ELISA Assay can be conveniently used to determine osteoclast number in human osteoclast cultures.

High amounts of tartrate-resistant acid phosphatase (TRACP) are expressed by bone-resorbing osteoclasts and activated macrophages. Two forms of TRACP circulate in human blood, known as TRACP 5a and TRACP 5b. TRACP 5b is derived from osteoclasts and TRACP 5a from macrophages. Osteoclasts secrete TRACP 5b into the blood circulation as an active enzyme that is inactivated and degraded to fragments before it is removed from the circulation. Thus, TRACP 5b activity does not accumulate into the circulation in renal or hepatic failure.

All serum TRACP 5b activity is derived from osteoclasts. Diurnal variability of serum TRACP 5b activity is low and the levels are not affected by feeding, allowing sample collection at any time of day.

Drake MT et al., Effects of suppression of follicle-stimulating hormone secretion on bone resorption markers in postmenopausal women. J Clin Endocrinol Metab. 2010 Nov;95(11):5063-8.

Heervä E et al., Follow-up of six patients with neurofibromatosis 1-related osteoporosis treated with alendronate for 23 months. Calcif Tissue Int. 2014 Jun;94(6):608-12.

Hannon RA et al., Clinical performance of immunoreactive tartrate resistant acid phosphatase isoform 5b as a marker of bone resorption. 2004 Bone 34:187-194.