Description

• General description: Dextran is a polymer of anhydroglucose. It is composed of approximately 95% α-D-(166) linkages. The remaining (163) linkages account for the branching of dextran.[1][2] Native dextran has been found to have a molecular weight (MW) in the range of 9 million to 500 million.[3] FITC-dextran has an excitation maximum of 490 nm. It has a pH range of 5 to 9. [4]
• Application: Dextran labeled with fluorescein isothiocyanate for possible use in perfusion studies in animals.
• Linkage: Similar to FD-40, but produced by Sigma.
• Preparation Note: Sigma typically tests the solubility of FITC dextrans in water at concentrations at or above 25 mg/ml. Solutions should be protected from light. In vivo, FITC-dextran is stable for more than 24 hours.
• Other Notes: Native dextran has been found to have a molecular weight (MW) in the range of 9 million to 500 million. Lower MW dextrans will exhibit slightly less branching and have a more narrow range of MW distribution. Dextrans with MW greater than 10,000 behave as if they are highly branched. As the MW increases, dextran molecules attain greater symmetry. Dextrans with MW of 2,000 to 10,000, exhibit the properties of an expandable coil. At MW below 2,000, dextran is more rod-like. The MW of dextran is measured by one or more of the following methods: low angle laser light scattering, size exclusion chromatography, copper-complexation and anthrone reagent colorometric reducing-end sugar determination and viscosity.