The PD-1[Biotinylated]:PD-L1 Homogeneous Assay Kit is designed to measure the inhibition of PD-1 binding to PD-L1. The PD-1[Biotinylated]:PD-L1 Homogeneous Assay Kit comes in a convenient AlphaLISA® format with purified biotinylated PD-1, FLAG-tagged PD-L1, and assay buffer to perform a total of 384 reactions. With this kit, only three simple steps on a microtiter plate are required. First, a sample containing biotinylated PD-1 and an inhibitor of choice is incubated with the FLAG-tagged PD-L1 for 60 minutes. Next, acceptor beads are added, then donor beads, followed by reading the Alpha-counts.