Nile red can be used to localize and quantify lipids, especially neutral lipid droplets in cells . Nile Red is almost non-fluorescent in water and other polar solvents, but exhibits fluorescence enhancement in non-polar environments, achieving a larger level of blue shift in absorption and emission wavelengths (the maximum excitation/emission wavelength in methanol is ∼ 552/636 nm). We recommend dissolving in high-quality anhydrous DMSO or DMF to achieve stock concentrations up to 1 mM.