Cell biology 

Applications
TNF-α can be used for a variety of applications, including:

• Induction of Mo-DC maturation.
• Cytotoxicity and cell proliferation assays.
• Assessment of apoptosis and viral protection.
• Investigation of TNF-α–induced signaling pathways.

Alternative names
TNFSF2

Background information
Tumor necrosis factor α (TNF-α) is a proinflammatory cytokine mainly produced by activated monocytes and macrophages in response to infection, injury, and tumor burden. TNF-α production has also been reported for a variety of other cell types involved in inflammatory responses, including T cells, NK cells, and neutrophils as well as a number of non-immune cells, such as keratinocytes and astrocytes. TNF-α has a broad spectrum of biological activities. In addition to its central role in inflammation, TNF-α is noted for its cytotoxic and tumoricidal abilities either by necrosis or induction of apoptosis. Further functions include antiviral activity, growth modulation, and induction of cellular differentiation. Despite its various beneficial actions, TNF-α also plays a detrimental role in, for example, septic shock syndrome, tissue injury, inflammation, cachexia, and diabetes.

Quality description
Research-grade cytokines are suitable for a wide variety of cell culture applications. They are sterile-filtered prior to lyophilization. Generally, endotoxin levels are <0.1 ng/μg (<1 EU/μg), and purities are >95%. The biological activity is tested in appropriate bioassays.
Premium-grade cytokines offer the convenience of high and well-defined biological activities and allow exact unit dosing for demanding applications. The biological activity is determined after lyophilization and reconstitution, and normalized to WHO/NIBSC standards whenever available. In general, endotoxin levels are <0.01 ng/μg (<0.1 EU/μg), and purities are >97%. Lot-specific certificates of analysis are available on request (macstec@miltenyibiotec.de).

Biological activity
Inhibition of L-929 cells (NIBSC 88/786)
premium grade: ≥ 4×10⁷ IU/mg (typical activity: ≥ 6×10⁷ IU/mg)
research grade: ≥ 2×10⁷ IU/mg