R&DPurity: >97%, by SDS-PAGE under reducing conditions and visualized by silver stain.
Endotoxin Level: <0.10 EU per 1 μg of the protein by the LAL method.
Activity: Measured in a cytotoxicity assay using L‑929 mouse fibroblast cells in the presence of the metabolic inhibitor actinomycin D. Matthews, N. and M.L. Neale (1987) in Lymphokines and Interferons, A Practical Approach. Clemens, M.J. et al. (eds): IRL Press. 221. The ED50 for this effect is 25-100 pg/mL.
The specific activity of Recombinant Human TNF-alpha is approximately 7.6 x 104 IU/μg, which is calibrated against human TNF-alpha WHO International Standard (NIBSC code: 88/786). Specific activity is for reference purposes only and is not routinely tested.
Source: E. coli-derived human TNF-alpha protein Val77-Leu233, with and without an N-terminal Met
N-terminal Sequence Analysis: Met & Val77
Predicted Molecular Mass: 17 kDa
SDS-PAGE: 17 kDa, reducing conditions