< 0.5% cross-reactivity observed with available related molecules.< 50% cross-species reactivity observed with species tested.
No significant interference observed with available related molecules.
The Quantikine Human SOST immunoassay is a 4.5 hour solid-phase
ELISA designed to measure SOST in human cell culture supernates,
serum, and plasma. It contains NS0-expressed recombinant human SOST and
antibodies raised against the recombinant factor. This immunoassay has
been shown to accurately quantitate the recombinant human SOST. Results
obtained using natural human SOST showed dose response curves
that were parallel to the standard curves obtained using the Quantikine
kit standards. These results indicate that this kit can be used to
determine relative mass values for natural SOST.
Intra-Assay Precision (Precision within an assay) Three samples of known concentration were tested on one plate to assess intra-assay precision.
Inter-Assay Precision (Precision between assays) Three samples of known concentration were tested in separate assays to assess inter-assay precision. Assays were performed by at least three technicians using two lots of components.
The recovery of SOST spiked to levels throughout the range of the assay in various matrices was evaluated.
Average % Recovery
Cell Culture Media (n=4)
EDTA Plasma (n=4)
Heparin Plasma (n=4)
To assess the linearity of the assay, samples containing and/or spiked
with high concentrations of human SOST were serially diluted with Calibrator Diluent to produce samples with values within the
dynamic range of the assay.
Preparation and Storage
Store the unopened product at 2 - 8 °C. Do not use past expiration date.
SOST, also known as Sclerostin, is a Cerberus/DAN family BMP antagonist and is an important regulator of bone homeostasis. Inactivating mutations in the SOST gene can cause sclerosteosis and van Buchem disease. SOST is expressed by terminally differentiated cells embedded in mineralized matrix including osteocytes, hypertrophic and prehypertrophic chondrocytes, and tooth cementocytes. Its expression is induced by BMP-2, -4, and -6 and is inhibited by parathyroid hormone (PTH). Its downregulation in osteocytes by physical loading of bone contributes to the mechanical sensor function of osteocytes and the subsequent increase in bone growth. SOST binds to BMP-2, -4, -5, -6, and -7 and inhibits the osteogenic differentiation induced by these BMPs. It inhibits canonical Wnt signaling by binding to LRP-5 and LRP-6 and inhibiting their association with Frizzled receptors. SOST reduces the proliferation of mesenchymal stem cells (MSC) and induces MSC apoptosis. Circulating levels of SOST are elevated in pathologies with bone involvement including low bone mineral density, Paget’s disease, multiple myeloma, and prostate cancer with bone metastases. It is also elevated in advanced chronic kidney disease, alcoholic liver disease, type 2 diabetes, and patients with increased abdominal and gynoid fat.