GM-CSF was initially characterized as a factor that can support the in vitro colony formation of granulocyte-macrophage progenitors. It is also a growth factor for erythroid，megakaryocyte，and eosinophil progenitors. GM-CSF is produced by a number of different cell types （including T cells，B cells，macrophages，mast cells，endothelial cells，fibroblasts，and adipocytes） in response to cytokine or inflammatory stimuli. On mature hematopoietic cells，GM-CSF is a survival factor for and activates the effector functions of granulocytes，monocytes/macrophages，and eosinophils. GM-CSF promotes a Th1 biased immune response，angiogenesis，allergic inflammation，and the development of autoimmunity. It shows clinical effectiveness in ameliorating chemotherapy-induced neutropenia，and GM-CSF transfected tumor cells are utilized as cancer vaccines. The 22kD glycosylated GM-CSF，similar to IL-3 and IL-5，is a cytokine with a core of four bundled alpha helices. Mature human GM-CSF shares 63% - 70%aa sequence identity with canine，feline，porcine，and rat GM-CSF and 54% with mouse GM-CSF. GM-CSF exerts its biological effects through a heterodimeric receptor complex composed of GM-CSF R alpha/CD116 and the signal transducing common beta chain （CD131） which is also a component of the high-affinity receptors for IL-3 and IL-5. In addition，GM-CSF binds a naturally occurring soluble form of GM-CSF R alpha. Human GM-CSF is active on canine and feline cells but not on murine cells.Sample Type：Cell culture supernatants，serum，plasma，and tissueIntended Use：The Human GM-CSF BioAssay ELISA Kit is an enzyme-linked immunosorbent assay for the quantitative detection of Human GM-CSF concentrations in cell culture supernatants，serum，plasma，and tissue.Sensitivity：4pg/mlRange：15.625-1000pg/mlSpecificity：Recognizes human GM-CSF.Sample Volume：100ul/wellTest Principle：This assay employs the Sandwich immunoassay technique. An anti-h GM-CS Fmonoclonal coating antibody is adsorbed onto microwells. GM-CSF 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 GM-CSF antibody is added and binds to GM-CSF captured by the first antibody. Following incubation unbound Biotinylated anti-h GM-CSF antibody is removed during a wash step. A Streptavidin-HRP is added and binds to Biotinylated anti-h GM-CSF antibody. Following incubation unbound Streptavidin-HRP is removed during a wash step. A colored product is formed in proportion to the amount of GM-CSF 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 GM-CSF standard dilutions and GM-CSF 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.
