Human TNFalpha ELISA Kit

Tumor necrosis factor alpha (TNFalpha or TNF) is secreted by macrophages in response to inflammation, infection, and cancer. Human Tumor Necrosis Factor (TNF) and Lymphotoxin (TNFalpha) are cytotoxic proteins which have similar biological activities and share 30% amino acid homology. TNFalpha is produced by monocytes, which can stimulate endothelial cells to produce the multi-lineage growth factor granulocyte-macrophage colony-stimulating factor (GM-CSF) and extend the role of this immunoregulatory protein to the regulation of hematopoiesis in vitro. TNF is a soluble protein that causes damage to tumor cells, but has no effect on normal cells. Human TNF has been purified to apparent homogeneity as a 17.3kDa protein from HL-60 leukemia cells and has shown 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. TNFalpha has been mapped to human chromosome 6. ScienCell's human TNFalpha ELISA Kit is based on standard sandwich enzyme-linked immune-sorbent assay technology. Human TNFalpha-specific monoclonal antibodies are pre-coated onto 8 x 12 strips. The human-specific detection polyclonal antibodies are biotinylated. The test samples and biotinylated detection antibodies are subsequently added to the wells and then washed with PBS or TBS buffer. Avidin-Biotin-Peroxidase Complex is added and unbound conjugates are washed away with PBS or TBS buffer. HRP substrate TMB is used to visualize HRP enzymatic reaction. TMB is catalyzed by HRP to produce a blue color product that changes to yellow after adding acidic stop solution. The intensity of yellow is proportional to the amount of human TNFalpha in the sample that is captured on the strips.