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TNF-a 50% OFF* Print version *on second equal size Tumor Necrosis Factor-Alpha (TNF-a), also
known as cachectin, is named after its activity to
cause tumor necrosis in vivo when
injected into tumor-bearing mice. TNF-a is expressed as a 26 kDa membrane bound protein and is then cleaved by TNF-a
converting enzyme (TACE) to release the soluble 17 kDa
monomer which forms homotrimers in circulation.
Recombinant TNF-a exists as homo-dimer,
-trimer or -pentamer.
TNF-a is believed to play
roles in antitumor activity, immune modulation, inflammation, anorexia, cachexia, septic
shock, viral replication and ematopoiesis. TNF-a is expressed in many types of cells but
primarily in macrophage cells in response to immunological challenges such as bacteria (lipopolysaccharides),
viruses, parasites, mitogens and other cytokines.
TNF-a is closely related to
the 25 kDa protein Tumor Necrosis Factor-b (lymphotoxin)
with 28% amino acid sequence identity, sharing the same receptors (TNFR1 and
TNFR2) and cellular actions. TNF-a causes cytolysis or cytostasis
of many transformed cells, being synergistic with g -interferon in its cytotoxicity. Although it has little effect on many
cultured normal human cells, TNF-a appears to be
directly toxic to vascular endothelial cells. Other actions of TNF-a include stimulating growth of human fibroblasts and
other cell lines, activating polymorphonuclear neutrophils and osteoclasts,
and induction of interleukin-1, prostaglandin E2 and collagenase
production. Although TNF-a is currently being evaluated in treatment of
certain cancers and AIDS-related symptoms, the recombinant TNF-a offered by Biomyx is for research only. |
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Phone:(858) 457-3658 Fax:(858) 457-3485 Emails
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Recombinant
Human Tumor Necrosis Factor a CAS Number: 94948591
MDL Number: MFCD00148692
Catalog# Package size Price
T1100-20 20µg $299 T1100-200 200µg $750 T1100-1000 1.0mg $1999 *offer valid on second item of
equal size when you purchase one item (catalog numbers T1100-20, -200 or
-1000) at list price. Formulation:
Powder lyophilized from volatile
buffer 50mM NH4HCO3
(pH 8.0). Preservative: None. MW: 17kDa Purity: >97% (15%
SDS-PAGE) Source: Recombinant
protein expressed in E. coli. Sterility: 0.2 µm membrane-filtered and packaged
aseptically. ED50*: 0.01-0.1ng/ml. Endotoxin**: ≤0.1
EU/mg TNF-a QC Tests: SDS-PAGE, Native PAGE, ELISA, Cytolysis, TC |
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Reconstitution and Use: Reconstitute the contents of the vial using sterile phosphate-buffered saline (PBS) to a concentration no less than 100 mg/ml and aliquot for future use. (If the initial rehydration is too diluting, activity may be lost due to the non-specific adsorption to the container). The solution can then be further diluted to a working stock solution. Bovine serum albumin can be added to the working solution to protect TNF-a from loss at low concentrations. If the product is going to be used for
applications requiring absolute asepsis (e.g. cell culture), it’s best to
filter-sterilize the solution using a sterile and non-pyrogenic
0.2µm membrane before
use. Storage
and Stability: Upon receiving, store the product at -20 °C.
After reconstitution, store the working aliquots at 2-8 °C for no more than 3 months. For
extended storage, aliquot the rehydrated solution (³100 mg/ml) and freeze at -70 °C or -20 °C. Avoid repeated freezing and
thawing. More dilute solutions stored at -20 °C will lose activity faster. *Cytolysis
Assay: The ED50 is defined as the
effective concentration of TNF-a that causes 50% cytolysis of murine L929B cells, a TNF-a sensitive mouse fibrosarcoma
cell line, in the presence of actinomycin-D.
Results may vary depending on cell line used. (Havell,
E.A., 1987). |
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**Endotoxin Assay: Endotoxin Unit (EU) is determined by Limulus Amebocyte Lysate (LAL) assay (Sigma). Further information: 1) Aggarwal, B., and Reddy, S., Nicola, N., ed.,
Tumor necrosis factor (TNF) Guidebook to
Cytokines and Their Receptors , 2) Beutler, B., Sporn,
M., and Roberts, A, ed., cachectin/tumor necrosis
factor and lymphotoxin Peptide Growth Factors and their Receptors II , 3) Callard, R., and Gearing, A., The Cytokine Facts Book , 4) Ruff, M.R. and G.E. Gifford, Lymphokines 2: 235,
1981. 5) Eskandari, M.K., et al., Immunol. Invest. 19: 69-79, 1990. 6) Havell, E.A., J. Immunol.
139: 4225-4231, 1987. 7) Ware, C., et al., Thomson, A.W., ed.,
Tumor necrosis factor-related ligands and
receptors. The Cytokine Handbook
3rd ed., , 8) Matthews, N., et al., Lymphokines and Interferons, A
Practical Approach, Clemens, M., et al., eds. IRL Press, 221 (1987). |
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ã2004 Biomyx Technology · |
