DNA damage and cell cycle analysis by flow cytometry

Double stranded DNA breaks were quantified by flow cytometry through measuring phosphorylation of ATM and γH2AX using a commercially available kit (Muse Multi-Color DNA Damage Kit, Millipore) on a Muse Cell Analyzer (Millipore, Billerica MA). Neuroblastoma cells were treated with 37 kBq/mL of [²¹¹At]MM4 or 0.1% ethanol vehicle control for 1, 4, or 24 h, and then handled according to the commercial protocol for the Multi-Color DNA Damage Kit. Cell cycle analysis was performed using the same treatment followed by propidium iodide staining using a Muse Cell Cycle Assay Kit on the Muse Cell Analyzer. Experiments were completed three independent times.