How does BrdU (Bromodeoxyuridine) cause mutation?

BrdU (Bromodeoxyuridine) is an analog of thymidine, one of the building blocks of DNA. It is widely used in cell proliferation cells to identify and monitor cells that are dividing. These assays help in the study of neurogenesis or the generation of neurons in the developing brain.

When administered to animals via injection or oral administration, BrdU becomes incorporated into the newly synthesized DNA, allowing researchers to identify and study proliferating cells. Although BrdU is effective for the purpose, its structure is markedly different from that of thymidine. This inherently different structure is the main cause behind the random mutations that occur during BrdU assays. These have unpredictable effects on the cells being monitored.