Oil Red O Staining and Quantification

After incubation with palmitic acid (100 μM, 24 hours) complexed with 0.2% albumin, cells were fixed with paraformaldehyde (4%, 10 minutes at room temperature), rinsed with PBS, and stained with the Oil Red O (0.5%; Biovision; 5 minutes at room temperature) as previously described.¹² Stained cells were rinsed with PBS and viewed with a Leica Dmi8 inverted light microscope. For quantification, Oil Red O was incubated for 30 minutes and washed with PBS and then 60% isopropanol. Oil Red O was eluted with isopropanol (100%, 10 minutes at room temperature) followed by eluate absorbance measurement at 492 nm with a NanoDrop 2000 spectrophotometer (Thermo Fisher Scientific).