The PD-L1:B7-1[Biotinylated] Inhibitor Screening Assay Kit is designed for screening and profiling inhibitors of the PD-L1:B7-1 interaction. The key to this kit is the high sensitivity of detection of biotin-labeled B7-1 by streptavidin-HRP. Only a few simple steps on a microtiter plate are required for the assay. First, PD-L1 is coated on a 96-well plate. Next, B7-1-biotin is incubated with PD-L1 on the plate. Finally, the plate is treated with streptavidin-HRP followed by addition of an HRP substrate to produce chemiluminescence, which can then be measured using a chemiluminescence reader.