Description_x000D_ General description_x000D_ Fas Ligand (FasL) is a member of the TNF superfamily that is expressed on the cell surface of activated T cells. Binding of FasL to Fas Receptor triggers apoptosis in Fas-bearing cells. FasL has the ability to kill T cells and activated B cells which leads to down-regulation of the immune response. The mechanism of Fas induced apoptosis involves recruitment of procaspase 8 through an adaptor molecule called FADD followed by processing of the pro-enzyme to active forms. These active caspases then cleave various cellular substrates leading to the eventual cell death. Both human and murine sFasL are fully active on human and murine cells. Recombinant human soluble Fas Ligand is a 17.9 kDa protein comprising the TNF homologous region of FasL and contains an 8 residue N-terminal His-Tag._x000D_ Physical form_x000D_ Sterile filtered through a 0.2 micron filter. Lyophilized from 0.5x PBS, pH 7.5._x000D_ Reconstitution_x000D_ Centrifuge the vial prior to opening. Reconstitute in water to a concentration of 0.1-1.0 mg/mL. Do not vortex. This solution can be stored at 2-8°C for up to 1 week. For extended storage, it is recommended to further dilute in a buffer containing a carrier protein (example 0.1% BSA) and store in working aliquots at -20°C to -80°C.