The CTLA4[Biotinylated]:B7-2 Inhibitor Screening Assay Kit is designed for screening and profiling inhibitors of CTLA4:B7-2 interaction. The key to this kit is the high sensitivity of detection of biotin-labeled CTLA4 by streptavidin-HRP. Only a few simple steps on a microtiter plate are required for the assay. First, B7-2 is coated on a 96-well plate. Next, CTLA4-biotin is incubated with B7-2 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.