Fig. 2.

Hypoxia exposure for 24 h reduced the apoptosis of CSCs. (A) Apoptosis of CSCs was evaluated by flow cytometry: (a, b) apoptosis rate of CSCs that experienced 12 h normoxia or hypoxia exposure respectively; (c, d) apoptosis rate of CSCs that experienced 24 - normoxia or hypoxia exposure respectively. Quadrant cells were divided into four sections: Q1, Annexin V⁻FITC⁻PI⁺, mechanical error; Q2, Annexin V⁻FITC⁺PI⁺, late apoptosis or necrosis cells; Q3, Annexin V⁻FITC⁻PI⁻, viable cells; Q4, Annexin V⁻FITC⁺PI⁻, early apoptosis cells. (B) Comparison of apoptosis between normoxia and hypoxia groups at 12 and 24 h. n = 3, **p < 0.01 vs normoxia. FITC fluorescein isothiocyanate, PE phycoerythrin