Sulfobromophthalein (Bromosulfophthalein) disodium salt is an organic anion dye used in the study of a variety of membrane carriers expressed in animal tissues and involved in transport of drugs and metabolites.In Vitro: Sulfobromophthalein disodium salt is a synthetic dye introduced in 1925 as a clinical tool aiming at the assessment of the liver function.
Sulfobromophthalein (BSP) is a pH indicator dye, featured by fast (17), protondependent quinoidal–phenolic tautomerism (pK = 8.5) .
Bromosulfalein has been commonly used as both a substrate and inhibitor of organic anionic transporting polypeptide 1B1 (OATP1B1), OATP1B3, OATP1A2, and OATP2B1, as well as multidrug resistance protein 2 (MDR2) [2].