*4.8. Senescence-Associated* β*-Galactosidase (SA-*β*-Gal) Assay*

Cells seeded on coverslips were stained with SA-β-Gal following manufacturer's instructions (Senescent Cell Histochemical Staining Kit, Sigma-Aldrich, St. Louis, MO, USA). Blue stained cells expressing β-galactosidase (senescent cells) were observed under bright-field microscopy using differential interference contrast.
