Recombinant Human TNF-alpha

The lyophilized protein is stable at 2-8C. Upon receipt, store desiccated at -20C. After reconstitution, the preparation is stable for up to one week at 2-8C. For maximal stability, apportion the reconstituted preparation into working aliquots and store at -20C to -80C. For long term storage of reconstituted protein, it is recommended that a carrier protein such as 0.1% BSA or HSA be added. This depends on the particular application. Avoid repeated freeze/thaw cycles.

Tumor necrosis factor alpha (TNF-alpha), also called cachectin, is produced by neutrophils, activated lymphocytes, macrophages, NK cells, LAK cells, astrocytes endothelial cells, smooth muscle cells and some transformed cells. TNF-alpha occurs as a secreted, soluble form and as a membrane-anchored form, both of which are biologically active. The naturally-occurring form of TNF-alpha is glycosylated, but non-glycosylated recombinant TNF-alpha has comparable biological activity. The biologically active native form of TNF-alpha is reportedly a trimer. Human and mouse TNF-alpha show approximately 79% homology at the amino acid level and cross reactivity between the two species. Two types of receptors for TNF-alpha have been described and virtually all cell types studied show the presence of one or both of these types. Recombinant Human TNF-alpha is a single, non-glycosylated polypeptide chain containing 158 amino acids.

Centrifuge vial prior to opening. Add sterile distilled water or aqueous buffer to a concentration of 0.1-1.0 mg/ml. Further dilutions should be made in appropriate buffered solutions.

Fully biologically active when compared to the standard. The ED50 as determined by a cytotoxicity assay using mouse L929 cells is < 0.05 ng/ml, corresponding to a specific activity of >2 x 107 IU/mg in the presence of actinomycin D.