Application

Dextran labeled with fluorescein isothiocyanate for possible use in perfusion studies in animals.

Fluorescein isothiocyanate–dextran (FITC-dextran, fluorescein-dextran, FITC) was used in the following processes:Fluorescein-dextran microscopy.To evaluate the in vivo pulmonary vascular permeability in polymorphonuclear leukocyte α-defensins expressing transgenic mice.To quantify endocytic activity by flow cytometry.To label α-lactalbumin and ribonuclease.FITC-dextran is suitable for extensive microcirculation and cell permeability research utilizing microfluorimetry. It is also suitable for the study of plant cell wall porosity and capillary permeability.

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. Native dextran has been found to have a molecular weight (MW) in the range of 9 million to 500 million. FITC-dextran has an excitation maximum of 490 nm. It has a pH range of 5 to 9.

Linkage

Similar to FD-40, but produced by Sigma.

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.

Packaging

1 g in poly bottle

100, 250 mg in poly bottle

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.