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Product Line: Life Science

Fluorescein isothiocyanate

CAS 27072-45-3

Molecular structure of Fluorescein isothiocyanate

CAS · 27072-45-3

01

Product Overview

Fluorescein isothiocyanate is a high-purity fluorescein supplied for industrial and specialty chemical applications. Contact our team for specifications, packaging options and lead times.

02

Product Specifications

Appearance: Yellow solid
Purity (HPLC): 95% min
MS: 390
HNMR: Conforms
03

Applications

1. Bioconjugation and Fluorescent Labeling

The isothiocyanate functional group allows FITC to covalently bind to primary amines in proteins, peptides, antibodies, and other biomolecules.

Commonly used to produce fluorescent antibody conjugates for immunofluorescence, flow cytometry, and cell imaging.

2. Fluorescence Microscopy

FITC-labeled biomolecules enable high-contrast, green-fluorescent imaging of cells, tissues, and molecular interactions.

Applied in confocal, wide-field, and live-cell microscopy.

3. Flow Cytometry and FACS

One of the most widely used fluorophores in flow cytometry panels due to its brightness and compatibility with standard filter sets.

Useful for tracking cell surface proteins, intracellular markers, and cell viability.

4. Enzyme and Binding Assays

FITC is used in fluorescent assays to study enzyme kinetics, molecular binding events, and protein–ligand interactions.

FITC-labeled peptides or inhibitors serve as substrates or probes in competitive binding studies.

5. DNA/RNA and Oligonucleotide Labeling

Used to label oligonucleotides for hybridization assays, FISH, and real-time PCR.

Provides clear signal detection in nucleic acid assays.

04

Benefits

1. Strong Fluorescence Signal

Emits bright green fluorescence with high quantum yield.

Suitable for high-sensitivity detection and low-abundance targets.

2. Reactive and Stable Isothiocyanate Group

Forms stable thiourea linkages with amine groups in biomolecules under mild conditions.

Allows precise and durable fluorescent labeling.

3. Broad Compatibility

Can be conjugated to a wide range of molecules, including proteins, peptides, oligonucleotides, and synthetic polymers.

Works well in diverse applications, from basic research to clinical diagnostics.

4. Well-Characterized Performance

FITC is extensively studied, with well-established labeling protocols, spectral properties, and instrument compatibility.

Easily multiplexed with other fluorophores in multi-color experiments.

5. Low Cytotoxicity

Compatible with live-cell imaging at appropriate concentrations.

Minimal interference with most biological processes.

05

Conclusion

Fluorescein isothiocyanate (CAS 27072-45-3) is a powerful and versatile green fluorescent labeling reagent used in bioconjugation, microscopy, flow cytometry, enzyme assays, and nucleic acid detection. Its isothiocyanate group ensures efficient and stable covalent attachment to biomolecules, while its bright fluorescence supports sensitive and specific detection. This makes FITC an essential tool in biomedical research, diagnostics, and molecular biology workflows.

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