FasL-Strep Apoptosis Assays

FasL-Strep, a stable homotrimer, efficiently induces the CD95 pathway of apoptosis and is highly suited for evaluation of CD95 (Fas) receptor-ligand interaction.

Human or murine FasL-Strep (CD95L-T4) is an engineered human or murine Fas (CD95) ligand. C-terminal fusion of the T4-FOLDON to the extracellular FasL (CD95L) receptor-binding domain (E142-L281) results in bioactive, conformationally stabilized, well defined trimers, in contrast to commonly used N-terminal fused coiled-coil structures. Crosslinking is not required.

Human and murine FasL-Strep is available as single reagent (2.5 µg or 4x2.5µg).

In the heterogeneous apoptosis assay format, the FasL-Strep molecule is immobilized on Strep-Tactin® (the cognitive receptor of Strep-tag®) coated microplates. After addition of the cells to be investigated, caspase 3/7 activity is determined for measuring extent of apoptosis.

The FasL-Strep apoptosis assay described above is robust and reproducible due to the high stability of the FasL-Strep reagent. The test is easy to perform since common reagents are applied for read out. These properties identify this assay as an ideal basis for HTS assays for screening anti-apoptotic molecules.

The assay is available for human or murine FasL-Strep on Strep-Tactin® coated microplates.

Components of the Heterogeneous FasL-Strep Apoptosis Assay are:
2.5 µg FasL-Strep (human or murine, respectively) and 1 Strep-Tactin® coated microplate, 96-well.

The homogeneous FasL-Strep Apoptosis Assay can be performed in the presence of the anti-Strep-tag® antibody ""StrepMAB-Immo"" which increases apoptotic activity of FasL-Strep. The homogeneous FasL-Strep assay enables the quantitative determination of anti-apoptotic agents as shown by Fas-Fc competition. The measurement of apoptosis in the respective cells is achieved by determination of caspase 3/7 activity.

The assay is available with human or murine FasL-Strep and includes StrepMAB-Immo.