Fluorescein isothiocyanate-dextran | CAS 60842-46-8

Fluorescein isothiocyanate-dextran is a fluorescein-based, water-soluble dextran conjugate widely used as a fluorescent tracer and labeling macromolecule in biochemical and materials research. The fluorescein isothiocyanate moiety provides strong green fluorescence for visualization and quantification, while the dextran backbone offers inert, high-molecular-weight behavior that supports diffusion, uptake studies, and labeling of porous or polymeric systems. This combination makes the reagent useful for tracking transport, permeability, and distribution in microscopy, spectroscopy, and fluorescence-based assay workflows.

1. Fluorescent Tracer Studies

Fluorescein isothiocyanate-dextran is frequently used by cell biology and biomaterials researchers to quantify transport and diffusion in experimental systems where a macromolecular probe is required. In microscopy-based studies, the fluorescent dextran enables visualization of how bulk solutes move through hydrogels, extracellular matrix mimics, and porous scaffolds, supporting analysis of penetration depth and spatial distribution. In solution or plate-based workflows, the dye's fluorescence readout is commonly used to monitor release kinetics from polymer matrices or to compare relative permeability between formulations.

2. Microscopy Imaging Of Uptake

Fluorescein isothiocyanate-dextran is used as a macromolecular imaging reagent for examining uptake and intracellular or compartmental distribution in fluorescence microscopy experiments. Researchers employ dextran conjugates to track endocytic trafficking, vesicular transport, and compartment mixing because the polymeric scaffold behaves as a size-defined tracer rather than a small-molecule dye. The fluorescein signal supports straightforward localization studies in standard fluorescence imaging setups, including time-lapse experiments that follow changes in distribution over experimental time.

3. Hydrogel And Porous Material Labeling

Fluorescein isothiocyanate-dextran is applied in materials science workflows to label or probe transport behavior in hydrogels, membranes, and porous biomaterials. By incorporating the fluorescent dextran during fabrication or loading steps, researchers can map how macromolecules distribute within polymer networks and how network structure influences diffusion. This approach is also used to evaluate barrier properties and compare matrix architectures using fluorescence intensity profiles obtained from microscopy or imaging systems.

4. Flow Cytometry Tracing Assays

Fluorescein isothiocyanate-dextran is used in flow cytometry and fluorescence-based cell profiling workflows where a fluorescent macromolecular tracer is needed to report on uptake or exposure-dependent signal. In these studies, the dextran conjugate provides a convenient fluorescence handle for gating and quantifying cell-associated signal relative to experimental conditions, such as differences in incubation time or material-contact protocols. The reagent's macromolecular character supports experiments designed to distinguish bulk tracer association from small-molecule labeling behavior in multiplex-compatible fluorescence readouts.