Purity >98% by SDS-PAGE and RP-HPLC. Tumor Necrosis Factor-b Human Recombinant (Lymphotoxin) produced in E.Coli is a single, non-glycosylated, polypeptide chain containing 172 amino acids and having a molecular mass of 18645 Dalton. The TNF-b is purified by standard chromatographic techniques.