Flow Cytometry
Cells in logarithmic phase (1 × 106) were collected for cell cycle detection, cells were fixed with 70% cold ethanol, and stained with 1 mL propidium iodide (PI) dye (50 μg/mL; Becton Dickinson Biosciences, Mountain View, CA, USA) in dark for 30 min. Cell cycle was detected by fluorescein isothiocyanate (FITC) Calibur flow cytometry (Becton Dickinson Biosciences, Mountain View, CA, USA).
Then same amount of cells in logarithmic phase were collected for cells apoptosis detection, cells were suspended with 1 × Annexin buffer and stained with 5 μL Annexin-V-FITC (Becton Dickinson Biosciences, Mountain View, CA, USA) at room temperature for 10 min. Then cells were suspended with 300 μL of 1 × Annexin. The apoptosis rate was detected by flow cytometry.