Endostatin is a 20kD proteolytic fragment of the C-terminal，non-collagenous （NC1） domain of type XVIII Collagen. It was originally identified as a factor produced by murine hemangioendothelioma cells that could specifically inhibit endothelial cell proliferation and angiogenesis. Although the molecular signals that trigger the release of Endostatin from type XVIII Collagen are not well understood，multiple proteases have been suggested to be involved in its generation including Cathepsins S，B，L，and V，Elastase，and matrix metalloproteinases （MMPs）-2，-7，and -9. Endostatin is of particular interest as it has been shown to inhibit the growth of many primary and metastatic tumors. It may also be involved in down-regulating angiogenesis during physiological processes such as wound healing and the establishment of placental circulation. The anti-angiogenic activity of Endostatin is attributable to its ability to inhibit endothelial cell proliferation and suppress VEGF-and FGF basic-induced endothelial cell migration and adhesion. Many of these effects are thought to be mediated by interactions between Endostatin and endothelial cell-expressed Transglutaminase 2，Heparin，and Integrins alpha 5 beta 1 and alpha V beta 3.Sample Type：Cell culture supernatants，serum，plasma，and tissueIntended Use：The Human Endostatin BioAssay ELISA Kit is an enzyme-linked immunosorbent assay for the quantitative detection of Human Endostatin concentrations in cell culture supernatants，serum，plasma，and tissue.Sensitivity：30pg/mlRange：78-5000pg/mlSpecificity：Recognizes human Endostatin.Sample Volume：100ul/wellTest Principle：This assay employs the Sandwich immunoassay technique. An anti-h Endostatin monoclonal coating antibody is adsorbed onto microwells. Endostatin present in the sample or standard binds to antibodies adsorbed to the microwells. Following incubation unbound sample or standard are removed during a wash step. a Biotinylated anti-h Endostatin antibody is added and binds to Endostatin captured by the first antibody. Following incubation unbound Biotinylated anti-h Endostatin antibody is removed during a wash step. A Streptavidin-HRP is added and binds to Biotinylated anti-h Endostatin antibody. Following incubation unbound Streptavidin-HRP is removed during a wash step. A colored product is formed in proportion to the amount of Endostatin present in the sample. The reaction is terminated by addition of acid and absorbance is measured at 450nm. A standard curve is prepared from seven Endostatin standard dilutions and Endostatin sample concentration determined.Kit Components：Aluminium pouches with a Microwell Plate： 8x12Standard： 2xVialBiotinylated antibody： 2xVialStreptavidin-HRP： 2xVialAssay Buffer （25ml/Vial）： 2xVialWash Buffer Concentrate 20x （30ml/Vial）： 1xVialTMB Substrate Solution： 1x12mlStop Solution （12ml/Vial）： 1xVialPlate Covers- Adhesive strips： 3xstripsInstruction： 1xStorage 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.
