β-galactosidase assay
β-galactosidase assay was performed using Mammalian β-Galactosidase Assay Kit (Thermo Fisher Scientific, Inc.). Cells were plated in 96-well plate for 24 hours, after that washed with 100μL PBS (pH 7.2). A 100μL of β-Galactosidase Assay Reagent was added to each well and incubated for 30 minutes at 37°C. The reaction was stopped by adding 100μL of β-Galactosidase Assay Stop Solution. Absorbance of cells were measured at 405nm on BioTek Citation 5 Cell Imaging Multimode reader.