The anti-BrdU mouse monoclonal antibody (clone MoBU-1) Alexa Fluor(R) 488 conjugate for fluorescence microscopy exhibits high specificity for BrdU and no cross reactivity with the thymidine analog, EdU (5-ethynyl-2’-deoxyuridine) making this antibody ideal for BrdU cell proliferation assays, in particular applications that require multiple nucleoside analogs or a dual-pulse method. Additionally, this anti-BrdU antibody can be used to detect BrdUTP incorporated into DNA strand breaks as part of a TUNEL assay.