Safranine O staining
Chondrocytes were incubated with different concentrations (0, 1, and 5
μM) of empagliflozin with or without IL-1β (10 ng/ml) for 24 h. Then the
cells were fixed with 4% paraformaldehyde (PFA) solution for 20 min.
After washing with PBS, 0.1% Safranine O dye solution were added to
stain the cells for 5 min. After washing with PBS twice, cells were
imaged by gross camera.