bromide gas 5-Bromouridine (abbreviated BrUrd, 5BrU, br5Urd or rarely the one letter code B)[2] is a uridine derivative with a bromo substituent at the fifth carbon.

[3] BrUrd is incorporated into RNA and can be detected immunocytochemically and analysed by cytometry.

It causes DNA damage through base substitution and increases the number of mutations.

This method was used in Tani et al.'s study determining RNA half-lives to investigate the function of non-coding RNAs.

[6] Incorporation of 5-bromouridine by individual cells was detected immunocytochemically using antibodies against BrdU followed by flow cytometry.