Actively proliferating HeLa cells were exposed to JMN3-003 (10 mM), hydroxyurea (4 mM), or nocodazole (200 ng/ml) for 36 hours, followed by resuspension in buffer I (20 mM citrate/PO, pH 3.0, 0.1 mM EDTA, 0.2 M Sucrose, 0.1% Triton X-100) and staining in buffer II (10 mM Citrate/PO, pH 3.8, 0.1 M sodium chloride, 20 mg/ml acridine orange) as described [80] . Green fluorescence at 525 nm resulting from DNA intercalating acridine orange was then measured using a BD LSRII flow cytometer and FlowJo software (Tree Star) for data analysis. For comparison, unstained and stained, solvent-only exposed cells were examined in parallel.