Internucleosomal DNA fragmentation is a hallmark of apoptosis in mammalian cells. 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; H2O2/Urea tablets for color generation; and methyl green solution for counterstaining the cells. The kit provides convenient detection of DNA fragmentation in tissue sections and fixed cell preps. Results can be analyzed by fluorescence microscopy. Reagents are provided sufficient for 50 assays. BioVision, Inc., 800-891-9699, www.biovision.com.