G-CSF is a pleiotropic cytokine best known for its specific effects on the proliferation，differentiation，and activation of hematopoietic cells of the neutrophilic granulocyte lineage. It is produced mainly by monocytes and macrophages upon activation by endotoxin，TNF-alpha and IFN-gamma. Other cell types，including fibroblasts，endothelial cells，astrocytes and bone marrow stromal cells，can also secrete G-CSF after LPS，IL-1 or TNF-alpha activation. In addition，various carcinoma cell lines and myeloblastic leukemia cells can express G-CSF constitutively. In humans，two distinct cDNA clones for G-CSF，encoding 207 and 204aa precursor proteins，have been isolated. Both proteins have a 30aa signal peptide and have identical amino acid sequences except for a 3aa insertion （deletion） at the 35aa residue from the N-terminus of the mature protein. Human G-CSF is 73% identical at the amino acid level to mouse G-CSF and the two proteins show species cross-reactivity. In vitro，G-CSF stimulates growth，differentiation and functions of cells from the neutrophil lineage. It also has blast cell growth factor activity and can synergize with IL-3 to shorten the Go period of early hematopoietic progenitors. Consistent with its in vitro functions，G-CSF has been found to play important roles in defense against infection，in inflammation and repair，and in the maintenance of steady state hematopoiesis.Sample Type：Cell culture supernatants，serum，plasma，and tissueIntended Use：The Human G-CSF BioAssay ELISA Kit is an enzyme-linked immunosorbent assay for the quantitative detection of Human G-CSF concentrations in cell culture supernatants，serum，plasma，and tissue.Sensitivity：7pg/mlRange：15.625-1000pg/mlSpecificity：Recognizes human G-CSF.Sample Volume：100ul/wellTest Principle：This assay employs the Sandwich immunoassay technique. An anti-h G-CSF monoclonal coating antibody is adsorbed onto microwells. G-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 G-CSF antibody is added and binds to G-CSF captured by the first antibody. Following incubation unbound Biotinylated anti-h G-CSF antibody is removed during a wash step. A Streptavidin-HRP is added and binds to Biotinylated anti-h G-CSF antibody. Following incubation unbound Streptavidin-HRP is removed during a wash step. A colored product is formed in proportion to the amount of G-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 G-CSF standard dilutions and G-CSF sample concentration determined.Kit Components：Aluminium pouches with a Microwell Plate： 8x6Standard： 1xVialBiotinylated antibody： 1xVialStreptavidin-HRP： 1xVialAssay Buffer （25ml/Vial）： 1xVialWash Buffer Concentrate 20x （30ml/Vial）： 1xVialTMB Substrate Solution： 1x6mlStop Solution （12ml/Vial）： 1xVialPlate Covers- Adhesive strips： 2xstripsInstruction： 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.
