Oil red O staining of 3T3-L1 cells

On day 8, the extent of adipogenesis was measured by oil red O staining. Briefly, cells were washed three times with phosphate-buffered saline (PBS) and fixed for 30 min with 4% paraformaldehyde in PBS. After three times wash with PBS, fixed cells were incubated with 0.5% oil red O in isopropanol for 30 min using an adequate shaker. Cells were washes with PBS and were photographed under a light microscope for analysis. Oil red O dyes were dissolved in isopropanol and lipid accumulation was quantified by measuring the absorbance at 510 nm using a spectrophotometer.