anti-Bromodeoxyuridine (BrDU) antibody: Bromodeoxyuridine (5-bromo-2'-deoxyuridine, BrdU) is a synthetic thymidine nucleoside analog. BrdU is commonly used to allow the detection of growing or proliferating cells in living tissues. During the S-phase of cell division, DNA replication occurs, and BrdU can be incorporated into the newly synthesized DNA by substituting for naturally occurring thymidine. Antibodies specific for BrdU are subsequently used to detect the incorporated BrdU thymidine analog. This highlights cells that were actively replicating their DNA and is suggestive of actively growing cells. Antibody binding usually requires the DNA to be denatured, typically by exposing the cells to acid or heat.