Jurkat T-cell leukemia cells were treated with 10µM BrdU for 1.5 hours. The cells were then fixed in ETOH and stored overnight at =-20°C. An acid denaturation method was used to prepare the cells before labeling with BrdU mouse monoclonal antibody (Clone MoBU-1) Alexa Fluor® 488 *for flow cytometry* *100 tests* to detect the incorporated BrdU, each using 5 µL antibody conjugate labeling 1 x 10^6 cells. Proliferating cells are clearly distinguished from non-proliferating cells.