BrdU labeled MCF7 Slides

Bromodeoxyuridine (BrdU) is a thymidine analog which is selectively incorporated into the DNA of proliferating cells to provide a marker for the DNA being replicated during the S-phase of the cell cycle. The number of proliferating cells can then be quantified in cell lysates, cell suspensions or tissue sections using an antibody specific for BrdU. Previous methods of detecting DNA included the use of [3H]-thymidine, which would be incorporated into the DNA and the replicated DNA could then be quantified by autoradiography or scintillation counting. These methods are more difficult and require more cleanup due to the radioactive material. An immunohistochemical or immunocytochemical assay provides a much simpler and cleaner method for detecting replicating DNA in cells.