5-bromo-2-deoxyuridine, or BrdU, is a base analog of thymidine, which will substitute for thymidine in DNA. Because BrdU can replace thymidine during the S phase of cell division, it can cause mutations.

BrdU is a commonly used in the detection of proliferating cells in living tissues. It works by substituting for thymidine during DNA replication and incorporating itself into the newly synthesized DNA. Antibodies specific for BrdU can then be used to detect the incorporated chemical (see immunohistochemistry), thus indicating cells that were actively replicating their DNA (proliferating). Binding of the antibody is achieved by denaturation of the DNA, usually by exposing the cells to acid or heat. BrdU labeling is frequently used in conjunction with additional antibodies that reveal cell type, in what are known as "double-labeling" experiments.

External links

• BrdU incoporation during DNA replication - Jiayang Chien, Wellesley College