Internucleosomal DNA fragmentation is a hallmark of apoptosis in mammalian cells. BioVision's Apo-BrdU-IHCTM Kit is a two-color TUNEL (Terminal deoxynucleotide transferase dUTP Nick End Labeling) assay for labeling DNA breaks to detect apoptotic cells by immunohistochemistry. The kit contains positive/negative control slides for assessing reagent performance; reaction and blocking buffers for processing individual steps in the assay; proteinase K; terminal deoxynucleotidyl tranferase enzyme (TdT), bromodeoxyuridine triphosphate (Br-dUTP), biotin labeled antiBrdU antibody for labeling DNA breaks, horseradish peroxidase streptavidin conjugate, DAB, H?O?/Urea tablets for color generation and methyl green solution for counter staining the cells