BODIPY FL-DHPE

BODIPY FL-DHPE is a fluorescent lipid probe composed of phosphatidylethanolamine (DHPE) labeled with a BODIPY FL fluorophore, which is used for fluorescent labeling of cell membranes, differentiation between liposome membrane fusion and endocytic pathways, and studies of membrane dynamics. The two C16 alkyl chains of BODIPY FL-DHPE insert into the lipid bilayer of membranes, and its fluorescence exhibits concentration dependence: it exists as monomers and emits green fluorescence at low mole fractions; it forms dimers with a red-shifted emission peak at high mole fractions; this spectral change is independent of enzymes, pH, and membrane potential. When liposomes enter the plasma membrane via membrane fusion, the dye is diluted, leading to attenuation of the dimer peak and enhancement of the monomer peak; when entry occurs via endocytosis, the dye remains in endosomes at high concentration with no change in the dimer peak, allowing differentiation between the two uptake pathways. Ex = 488 nm; monomer Em = 515 nm, dimer Em ≈ 620 nm .