Fluorescein-thiourea-PEG6-acid | CAS 2055014-69-0

Fluorescein-thiourea-PEG6-acid is a fluorescein-based dye conjugated to a PEG6 linker and a thiourea motif, providing a water-compatible fluorescent scaffold for labeling and imaging workflows where a stable, hydrophilic handle is beneficial. The fluorescein chromophore supports green fluorescence readouts commonly used in molecular staining, fluorescence microscopy, and fluorescence-based assay development, while the PEG spacer helps improve solubility and reduces nonspecific interactions in conjugation and detection formats.

1. Fluorescent Labeling Tags

Fluorescein-thiourea-PEG6-acid is used as a fluorescent labeling component in research workflows that require a hydrophilic fluorescein reporter for biomolecule conjugates, polymer constructs, or surface-associated materials. Molecular biology and chemical biology teams incorporate this dye into labeling strategies to visualize binding events, track reagent localization, or monitor conjugate distribution in aqueous assay buffers. The PEG6 linker supports practical handling in labeling pipelines by helping maintain dispersion and reducing aggregation-related background in fluorescence measurements.

2. Fluorescence Microscopy Tracers

Fluorescein-thiourea-PEG6-acid is applied as a green fluorescent tracer for cellular imaging and materials microscopy studies where PEGylated dye conjugates are preferred for improved aqueous compatibility. Researchers use fluorescein-tagged constructs to follow uptake, wash-out behavior, or spatial distribution of labeled reagents in microscopy experiments, including labeling of biomolecule assemblies and dye-functionalized biomaterials. The thiourea-linked PEG scaffold helps maintain a consistent fluorescent probe presentation when incorporated into larger conjugates used for imaging readouts.

3. Fluorescence-Based Bioassay Development

Fluorescein-thiourea-PEG6-acid is commonly used in fluorescence assay development as a reporter dye for monitoring binding or interaction readouts in microplate and cuvette formats. Assay developers incorporate the fluorescein signal to quantify relative fluorescence changes associated with reagent incorporation, immobilization, or assay workflow steps that require a stable green-emitting dye. The PEG6 acid functionality supports formulation in aqueous systems and helps streamline assay reagent preparation for fluorescence measurement on standard plate readers and fluorescence spectrometers.

4. Biomaterial Surface Functionalization

Fluorescein-thiourea-PEG6-acid is leveraged in biomaterials science to introduce a fluorescent tag onto hydrogel, polymer, or surface-modified platforms for visualization of coating uniformity and spatial patterning. Materials groups use fluorescein-labeled, PEG-containing dye constructs to confirm surface coverage, track diffusion within porous matrices, or monitor labeled layer integrity during washing and incubation steps. This application is particularly useful when a hydrophilic fluorescein reporter is needed to reduce nonspecific adsorption and support consistent imaging contrast across material surfaces.