How it works!

  1. Cisbio assays contain tagged checkpoint proteins for receptor (Tag1-protein) and ligand (Tag2-ligand).
  2. The Tag1-protein and Tag2-ligand are detected by using anti-Tag1-donor (HTRF cryptate donor) and anti-Tag2-acceptor (HTRF XL665 acceptor), respectively.
  3. Protein-ligand binding brings the donor and acceptor antibodies into close proximity and triggers fluorescent resonance energy transfer (FRET) measured as HTRF – this specific signal is directly proportional to the protein/ligand interaction.
  4. Compounds of antibodies (shown as a green sphere in the graphic) that block protein/ligand interaction will also prevent HTRF.


The kits!


Cisbio Advantages

  • Homogenous add-and-read protocol – no wash steps!
  • Protocol validation with reference antibodies and compounds
  • Amenable to different size formats: 96- to 1536-well
  • Time saving – get your results in as little as one day!


Have questions about Cisbio assays? Email our Technical Specialists and we’ll help!