Sulforhodamine 101 DHPE is a fluorescent probe made from the conjugation of the phospholipid 1,2-dipalmitoyl-sn-glycero-3-PE to sulforhodamine 101, a red fluorescent dye that displays excitation/emission spectra of 586/605 nm, respectively. It integrates into phospholipid bilayers and has been used for imaging of solid supported lipid bilayers, detection of protein-ligand binding on bilayers, and to monitor colocalization of lipid probes in liposomes via resonance energy transfer ( RET ).