The PARP2 Colorimetric Activity Assay Kit is designed to measure PARP2 activity for screening and profiling applications. PARP2 is known to catalyze the NAD-dependent addition of poly(ADP-ribose) to histones. The key to the PARP2 Colorimetric Activity Assay is the biotinylated substrate. With this kit, only three simple steps are required for PARP2 reactions. First, histone proteins are coated on a 96-well plate. Next, the PARP2 biotinylated substrate is incubated with an assay buffer that contains the PARP2 enzyme. Finally, the plate is treated with streptavidin-HRP followed by addition of the colorimetric HRP substrate to produce color that can then be measured using a UV/Vis spectrophotometer microplate reader.