The LAG3:FGL1[Biotinylated] Inhibitor Screening Assay Kit is designed for screening and profiling inhibitors of LAG3:FGL1. The key to this kit is the high sensitivity of detection of biotin-labeled FGL1 by streptavidin-HRP. Only a few simple steps on a microtiter plate are required for the assay. First, LAG3 is attached on a nickel-coated 96-well plate. Next, biotinylated FGL1 is incubated with LAG3 on the plate. Finally, the plate is treated with streptavidin-HRP followed by addition of an HRP substrate to produce chemiluminescence, which can be measured using a chemiluminescence reader.