The lipid droplet (LD) has become a focus of intense research. Fluorescence labeling is indispensable for the cell biological analysis of the LD, and a lipophilic fluorescence dye, BODIPY 493/503, which emits bright green fluorescence has been used extensively for LD labeling. The dye is convenient for double fluorescence labeling, but we noticed that it emits red fluorescence under certain conditions, which could lead to erroneous interpretations. We propose a protocol to preclude such a possibility.