FITC-Dextran (MW 150000) is a fluorescent probe for fluorescein isothiocyanate (FITC) dextran (Ex=491 nm; Em=518 nm). FITC-Dextran (MW 150000) can be used as a marker to reveal heat shock-induced cell damage and to study the early and late stages of apoptosis. FITC-Dextran (MW 150000) can be used in perfusion studies in animals or in fluorescence microlymphography, to study processes that affect the permeability of the blood brain barrier (BBB). FITC-Dextran (MW 150000) can be used as fluorescent probe to study cell permeability.