Halo-Flipper is a fluorescent probe that specifically labels Halo-tag?* and reports membrane tension changes through its fluorescence lifetime changes. It contains a Chloroalcane Halo-tag?* ligand as well as a tethered Flipper fluorophore?which senses changes of the organization of lipid bilayer membranes surrounding the Halo-tag?* protein . Halo-Flipper?spontaneously labels Halotag expressing cells and is only fluorescent when inserted in a lipid membrane. It has a broad absorption and emission spectrum, excitation can be commonly performed with a 488nm laser, while emission is collected between 575 and 625nm. It is the perfect tool to precisely localize the Flipper-TR membrane tension fluorophore within cells. ChloroAlkane (CA) is the substrate of the self labeling tag Halo-tag?*. Upon reaction with a CA derivative, Halo-tag?* forms a covalent bond with the substrate. It allows to permanently attach a fluorescent label to any protein of interest (POI) expressed as Halo-tag?* fusion. Contains 1 vial of Halo-Flipper (lyophilized) *Halo-tag? is a registered trademark of Promega Corporation.