Bromodeoxyuridine (5-bromo-2'-deoxyuridine, BrdU, BUdR, BrdUrd) is a synthetic nucleoside that is an analog of thymidine. It can be incorporated into the newly synthesized DNA of replicating cells (during the S phase of the cell cycle), substituting for thymidine during DNA replication. As such, BrdU is used for birth dating and monitoring cell proliferation. BrdU is a toxic and mutagenic substance. It triggers cell death, the formation of teratomas, alters DNA stability, lengthens the cell cycle, and has mitogenic, transcriptional and translational effects on cells that incorporate it. This antibody does not cross react with Thymidine.