Annexin V-FITC/PI Apoptosis Assay

Cells in early and late apoptosis were quantified using an Annexin V-FITC/PI double staining assay kit (KGA107; Nanjing KeyGen Biotech Co., Ltd., Nanjing, China) as described previously (20 (link)). Cells were harvested by trypsinization and washed three times with PBS. Subsequently, 1×10⁵ cells from each 35 mm Petri dish were resuspended in 500 µl binding buffer and stained with 5 µl Annexin V and 5 µl PI in the dark at room temperature for 20 min. The stained cells were immediately examined using flow cytometry with an excitation wavelength of 488 nm for the green fluorescence of FITC-Annexin V and 561 nm for the red fluorescence of PI.