Insulin-like growth factor-binding protein-3 (IGFBP-3) is a major determinant of circulating levels of the IGFs and is clinically useful for the evaluation of GH deficiency and for predicting the response to GH treatment. The circulating level of IGFBP-3 is inversely related to the risk of several common cancers, and antiproliferative agents such as antiestrogens and retinoids act in part by up-regulating IGFBP-3 expression. IGFBP-3, well-characterized as the carrier of IGF, has been reported to have intrinsic bioactivity that is independent of IGF binding; IGFBP-3 has an IGF-independent, antiproliferative effect in undifferentiated and early differentiated, but not in terminally differentiated, chondrocytes. IGFBP-3 possesses both growth-inhibitory and potentiating effects on cells that are independent of IGF action and are mediated through specific IGFBP-3 binding proteins/receptors locate at the cell membrane, cytosol, or nuclear compartments and in the extra cellular matrix. IGFBP-3 is located on chromosome 7. The standard product used in this kit is recombinant human IGFBP-3, consisting of 265 amino acids with the molecular mass of 29kDa. As a result of glycosylation, the molecular mass is 41KDa.

ScienCell's human IGFBP-3 ELISA Kit is based on standard sandwich enzyme-linked immune-sorbent assay technology. Human IGFBP-3 specific-specific polyclonal antibodies are pre-coated onto 8 x 12 divisible strips. The human specific detection polyclonal antibodies are biotinylated. The test samples and biotinylated detection antibodies are subsequently added to the wells and then washed with PBS or TBS buffer. Avidin-Bioyin-Peroxidase Complex is added and unbound conjugates are washed away with PBS or TBS buffer. HRP substrate TMB is used to visualize HRP enzymatic reaction. TMB is catalyzed by HRP to produce a blue color product that changes into yellow after adding acidic stop solution. The intensity of yellow is proportional to the amount of human IGFBP-3 captured in strips.