Description
Principle of the assay: rat TNFalpha ELISA Kit was based on standard sandwich enzyme-linked immune-sorbent assay technology. A monoclonal antibody from mouse specific for TNFalpha has been precoated onto 96-well plates. Standards and test samples are added to the wells, a biotinylated detection polyclonal antibody from goat specific for TNFalpha is added subsequently and then followed by washing with PBS or TBS buffer. Avidin-Biotin-Peroxidase Complex was added and unbound conjugates were washed away with PBS or TBS buffer. HRP substrate TMB was used to visualize HRP enzymatic reaction. TMB was catalyzed by HRP to produce a blue color product that changed into yellow after adding acidic stop solution. The density of yellow is proportional to the rat TNFalpha amount of sample captured in plate.
Background: Tumor necrosis factor-alpha (TNF-alpha, or TNF) is secreted by macrophages in response to inflammation, infection and cancer.1 Human Tumor Necrosis Factor (TNF) and Lymphotoxin (TNF-beta) are cytotoxic proteinswhich have similar biological activities and share 30% amino acid homology.2 TNF-alpha is produced by monocytes,which can stimulate endothelial cells to produce the multilineage growth factor granulocyte-macrophage colony-stimulating factor and extend the role of this immunoregulatory protein to the regulation of hematopoiesis in vitro.3 TNF is a soluble protein that causes damage to tumor cells but has no effect on normal cells. Human TNFhas been purified to apparent homogeneity as a 17.3-kilodalton protein from HL-60 leukemia cells and has showed cytotoxic and cytostatic activities against various human tumor cell lines. The human TNF cDNA is 1585 base pairs in length and encodes a protein of 233 amino acids. The mature protein begins at residue 77, leaving a long leader sequence of 76 amino acids.4 TNF-alpha has been mapped to human chromosome 6.2