Technical Data
Tumor Necrosis Factor alpha, Recombinant, Human (TNFa)
Molecular Biology Storage: -20CShipping: Blue Ice
TNF is secreted by macrophages, monocytes, neutrophils, T-cells, NK-cells following their stimulation by bacterial LPS. Cells expressing CD4 secrete TNF-alpha while CD8 cells secrete little or no TNF-alpha. The synthesis of TNF-alpha is induced by many different stimuli including interferons, IL2, GM-CSF.

Recombinant Human Tumor Necrosis Factor-alpha is a single, non-glycosylated, polypeptide chain containing 158 amino acids and having a molecular mass of 17483.77 Dalton.

The sequence of the first five N-terminal amino acids was determined and was found to be Met-Val-Arg-Ser-Ser.

Dimers and Aggregates:
1% as determined by silver-stained SDS-PAGE gel analysis.

Biological Activity:
Recombinant Tumor Necrosis Factor-alpha is fully biologically active when compared to standard. The ED50 as determined by the cytolysis of murine L929 cells in the presence of Actinomycin D is less then 0.05ng/ml, corresponding to a Specific Activity of 2 x 10e7 IU/mg.

Protein Content:
Protein quantitation was carried out by two independent methods:
1. UV spectroscopy at 280 nm using the absorbency value of 1.24 as the extinction coefficient for a 0.1% (1mg/ml) solution. This value is calculated by the PC GENE computer analysis program of protein sequences (IntelliGenetics).
2. Analysis by RP-HPLC, using a calibrated solution of TNF-alpha as a Reference Standard.

Storage and Stability:
Lyophilized powder may be stored at 4C for short-term only. Reconstitute to nominal volume by adding sterile ddH2O, 0.1% HSA or BSA and store at -20C. Reconstituted product is stable for 12 months at -20C. For maximum recovery of product, centrifuge the original vial prior to removing the cap. Further dilutions can be made in assay buffer.
Source: Recombinant, Human (E. coli)
Purity: 95% by RP-HPLC, FPLC, or reducing/non-reducing SDS-PAGE Silver Stain. Chromatographically purified. Endotoxin: <0.1ng/ug (IEU/ug).
Concentration: ~0.1mg/ml
Form: Supplied as a liquid in 20mM PBS, pH 7.2, 0.1% BSA.

Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.
1. Early appearance of TNF-alpha and other cytokines in bronchus associated lymphoid tissues (BALT) from growing Wistar rats. what is the role of TNF-alpha? Delettieres D, Frecha CA, Clin Dev Immunol 2004 Sep-Dec;11(3-4):253-9 2. A novel mechanism for TNF-alpha regulation by p38 MAPK: involvement of NF-kappa B with implications for therapy in rheumatoid arthritis. Campbell J, Ciesielski CJ, Horwood NJ, Feldmann M, J Immunol 2004 Dec 1;173(11):6928-37 3. Echinacea alkylamides modulate TNF-alpha gene expression via cannabinoid receptor CB2 and multiple signal transduction pathways. Gertsch J, Schoop R, Suter A, FEBS Lett 2004 Nov 19;577(3):563-9 4. Expression and regulation of neuropilins and VEGF receptors by TNF-alpha in human endothelial cells. Yang H, Li M, Yan S, J Surg Res 2004 Dec;122(2):249-55 5. Implication of delayed TNF-alpha exposure on dendritic cell maturation and expansion from cryopreserved cord blood CD34+ hematopoietic progenitors. Xu RL, Tang Y, Malinowski K, J Immunol Methods 2004 Oct;293(1-2):169-82 6. Release of TNF-alpha from in vitro-stimulated monocytes is negatively associated with serum levels of apolipoprotein B in patients with type 2 diabetes. Zykova SN, Svartberg J, Iversen H, Scand J Immunol 2004 Nov;60(5):535-42.

Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.