The CD137:CD137L [Biotinylated] Inhibitor Screening Assay Kit is designed for screening and profiling inhibitors of CD137:CD137L interaction. The assay takes advantage of the highly sensitive detection of biotin-labeled CD137L by streptavidin-HRP. First, CD137 is coated on a 96-well plate. Next, CD137L-biotin is incubated with CD137. 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.