2.7. Measurement of Reactive Oxygen Species (ROS)

The accumulation of cellular ROS was detected by the fluorescence probe 2′,7′-dichlorofluorescein diacetate (DCFH-DA, D6883, Sigma-Aldrich, MO, USA). HUVECs cultured in 24-well plates were loaded with DCFH-DA (10 μM) in the dark for 20 min at 37°C, followed by washing with serum-free medium three times. Fluorescence was observed with the fluorescent microscope.