Insulin-like growth factor-binding protein 4 is a protein that in humans is encoded by the IGFBP4gene. This gene is a member of the insulin-like growth factor binding protein (IGFBP) family and encodes a protein with an IGFBP domain and a thyroglobulin type-I domain. The protein binds both insulin-like growth factors (IGFs) I and II and circulates in the plasma in both glycosylated and non-glycosylated forms. Binding of this protein prolongs the half-life of the IGFs and alters their interaction with cell surface receptors. In addition, IGFBP-4 is a unique protein and it consistently inhibits several cancer cells in vivo and in vitro. Its inhibitory action has been shown in vivo in prostate and colon. It is secreted by all colon cancer cells.
Sample Type:Cell culture supernates, serum and plasma (heparin, EDTA)
Intended Use:For quantitative detection of human IGFBP4 in cell culture supernates, serum, and plasma (heparin, EDTA).
Sensitivity:<20pg/ml
Range:500-32000pg/ml
Specificity:Natural and recombinant human IGFBP4
Test Principle:This human IGFBP4 BioAssay™ ELISA Kit was based on standard sandwich enzyme-linked immune-sorbent assay technology. A monoclonal antibody from mouse specific for IGFBP4 has been precoated onto 96-well plates. Standards (NSO) and test samples are added to the wells, a biotinylated detection polyclonal antibody from goat specific for IGFBP4 is added subsequently and then followed by washing with PBS or TBS buffer. Avidin-Biotin-Peroxidase Complex was added and unbound conjugates were washed away with PBS or TBS buffer. HRP substrate TMB was used to visualize HRP enzymatic reaction. TMB was catalyzed by HRP to produce a blue color product that changed into yellow after adding acidic stop solution. The density of yellow is proportional to the human IGFBP4 amount of sample captured in plate.
Kit Components:96-well plate precoated with human IGFBP4 antibody, 1Lyophilized recombinant human IGFBP4 standard, 40ng/tube×2Biotinylated human IGFBP4 antibody, 130ul (dilution 1:100)Avidin-Biotin-Peroxidase Complex (ABC), 130ul (dilution 1:100)Sample diluent buffer, 30mlAntibody diluent buffer, 12mlABC diluent buffer, 12mlTMB color developing agent, 10mlTMB stop solution, 10ml
Storage and Stability:Store powder at 4°C liquid at -20°C. Store other components at 4°C. Stable for at least 6 months For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
