Purity ≥ 98% by RP-HPLC, SDS-PAGE. Chromatographically purified. CD40L or CD154 is a membrane glycoprotein and differentiation antigen expressed on the surface of T-cells. The CD40 ligand stimulates B-cell proliferation and secretion of all immunoglobulin isotypes in the presence of cytokines. CD40 ligand has been shown to induce cytokine production and tumoricidal activity in peripheral blood monocytes. It also costimulates proliferation of activated T-cells and this is accompanied by the production of IFN-gamma, TNF-alpha, and IL2. Recombinant Human CD40L is a non-glycosylated, Polypeptide chain containing 149 amino acids and having a molecular mass of 16.3D. Sequence: The sequence of the first five N-terminal amino acids was determined and was found to be Met-Gln-Lys-Gly-Asp. Biological Activity: CD40L is fully biologically active when compared to standard. The ED50 as determined by the dose-dependent stimulation of IL-12 induction and IL-8 production by human PBMC (Peripheral Monon