Human TNF-Alpha ELISA Assay
The Human TNF-Alpha ELISA Assay is For Research Use Only
Size: 1×96 wells
Sensitivity: 25 pg/mL
Dynamic Range: 25-800 pg/ml
Incubation Time: 2.5 hours
Sample Type: Serum, Plasma, Cell Culture
Sample Size: 100 µl
Alternative Names: TNFSF1A, TNF-α, Tumor Necrosis Factor Alpha
Store kit reagents between 2-8C. Immediately after use remaining reagents should be returned to cold storage (2-8C). Expiry of the kit and reagents is stated on box front labels. The expiry of the kit components can only be guaranteed if the components are stored properly, and if, in case of repeated use of one component, the reagent is not contaminated by the first handling.
The Human TNF Alpha (TNF-α) ELISA employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for TNF-α has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any TNF-α present is bound by the immobilized antibody. Following incubation unbound samples are removed during a wash step, and then a detection antibody specific for TNF-α is added to the wells and binds to the combination of capture antibody- TNF-α in sample. Following a wash to remove any unbound combination, and enzyme conjugate is added to the wells. Following incubation and wash steps a substrate is added. A colored product is formed in proportion to the amount of TNF-α 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-α standard dilutions and TNF-α sample concentration determined.
TNF-Alpha ELISA Assay Kit
TNF-alpha Assay Ready Cells
The prototype ligand of the TNF superfamily, TNF-α/TNFSF1A, is a pleiotropic cytokine that plays a central role in inflammation and apoptosis (1-4). Human cells known to express TNF-α include B cells, colonic columnar epithelial cells, NK and CD3+CD56+ hepatic natural T cells, macrophages, monocytes and monocyte-derived dendritic cells, CD4+ and CD8+ T cells, mast cells, neutrophils, keratinocytes, plasma cells, and adipocytes.
It is synthesized as a 26 kDa, type II transmembrane protein that is 233 amino acids (aa) in length (4, 5). It contains a 30 aa cytoplasmic domain, a 26 aa transmembrane segment, and a 177 aa extracellular region (6, 7). TNF-α is assembled intracellularly to form a transmembrane, non-covalently-linked homotrimeric protein. The 157 aa residue soluble form of TNF-α (sTNF-α is released from the C-terminus of the transmembrane protein through the activity of TNF-α-converting enzyme (TACE), a membrane-bound disintegrin metalloproteinase (8, 9).
TNF-α is reported to promote inflammatory cell infiltration by upregulating leukocyte adhesion molecules on endothelial cells, serve as a chemotactic agent for monocytes, and activate phagocyte killing mechanisms (10). Deficiencies in either TNF-α or its receptors can increase susceptibility to infection by intracellular pathogens (11 – 12). TNF- may also play a role in lymphoid tissue development. Knockout mice lack splenic B cell follicles and the ability to form germinal centers (13, 14). Other potential physiological roles for TNF-α and its receptors include regulating the differentiation of hematopoietic stem and progenitor cells (15 – 17). TNF-α has been implicated in a number of pathophysiological processes. It is associated with unregulated pro-inflammatory activity and is thought to be a critical mediator of endotoxin-induced septic shock (18). Cachexia (or whole body wasting) has also been associated with long-term circulating TNF-α.