Annexin V binding. MOLM13 cells (5 × 10⁵/mL) were plated in 24-well plates and cultured with various concentrations of AZD1152-HQPA (1-10 nM). After 24 or 48 hours, cells were harvested, and annexin V binding and propidium iodide (PI) staining was analyzed by FACScan. Lower left quadrants show viable cells. Lower right quadrants show early apoptotic cells (annexin V⁺, PI⁻). Upper right quadrants show nonviable, late apoptotic/necrotic cells (annexin V⁺ and PI⁺). The numeric results represent the mean of triplicate plates, and a representative experiment is shown.