Tumor necrosis factor alpha （TNF-alpha），also known as cachectin; and tumor necrosis factor beta （TNF-alpha），also known as lymphotoxin，are two closely related proteins （approximately 34%aa sequence identity） that bind to the same cell surface receptors and show many common biological functions. TNF-alpha and -beta play a critical role in normal host resistance to infection and to the growth of malignant tumors，serving as immunostimulants and as mediators of the inflammatory response. Over-production of TNFs，however，has been implicated as playing a role in a number of pathological conditions，including cachexia，septic shock，and autoimmune disorders. TNF-alpha is produced by activated macrophages and other cell types including T and B cells，NK cells，LAK cells，astrocytes，endothelial cells，smooth muscle cells and some tumor cells. Rat TNF-alpha cDNA encodes a 235aa residue type II membrane protein.Sample Type：Cell culture supernatants，serum，plasma，and tissueIntended Use：The Rat TNF-alpha BioAssay ELISA Kit is an enzyme-linked immunosorbent assay for the quantitative detection of Rat TNF-alpha concentrations in cell culture supernatants，serum，plasma，and tissue.Sensitivity：15pg/mlRange：31.25-2000pg/mlSpecificity：Recognizes rat TNF-alpha.Sample Volume：100ul/wellTest Principle：This assay employs the Sandwich immunoassay technique. An anti-r TNF-alpha monoclonal coating antibody is adsorbed onto microwells. TNF-alpha 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-r TNF-alpha antibody is added and binds to TNF-alpha captured by the first antibody. Following incubation unbound Biotinylated anti-r TNF-alpha antibody is removed during a wash step. A Streptavidin-HRP is added and binds to Biotinylated anti-r TNF-alpha antibody. Following incubation unbound Streptavidin-HRP is removed during a wash step. A colored product is formed in proportion to the amount of TNF-alpha 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 TNF-alpha standard dilutions and TNF-alpha 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.
