Red Dye for Staining of Fat Cells and Lipids

Oil red O is a diazo dye which has been widely used for staining fat cell and lipids since long ago.^1-3) This lysochrome (fat-soluble dye) red dye can be used for staining of neutral triglycerides and low polar lipids. Oil Red O staining is done on fresh or frozen samples, since alcohol fixation removes lipid. Its usage is simple, and requires only washing after adding the staining solution, which makes it easy to identify lipids visually. Furthermore, accumulation of lipids can be quantified by eluting the dye using isopropanol after staining and measuring the absorbance. In this way, oil red O has been used in diabetes, hepatitis and leukemia research, for instance.^4,5)