5-Carboxyfluorescein

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

1. Fluorescent Bioconjugation and Labeling

The carboxylic acid group enables covalent attachment to amine-containing biomolecules (e.g., proteins, peptides, oligonucleotides) through amide bond formation using EDC/NHS chemistry.

Commonly used to label antibodies, enzymes, and nucleic acids for tracking, imaging, and assay development.

2. Fluorescence Microscopy and Imaging

Exhibits strong green fluorescence (excitation ≈ 494 nm, emission ≈ 518 nm).

Suitable for use in live-cell and fixed-cell fluorescence microscopy, confocal imaging, and high-content screening.

3. Flow Cytometry and FACS

Widely used for fluorescent staining of cells in flow cytometry, allowing analysis of cell surface markers, viability, and intracellular targets.

4. DNA/RNA and Oligonucleotide Labeling

Used for labeling oligos and probes in real-time PCR, FISH, and nucleic acid hybridization assays.

Ensures defined labeling location for quantitative and diagnostic accuracy.

5. Sensors and Assays

Serves as a component of fluorescent probes, enzyme substrates, and pH-sensitive dyes in chemical and biological detection systems.

1. Single Isomer Purity

Offers greater consistency and reproducibility than mixed-isomer alternatives (e.g., 5(6)-carboxyfluorescein).

Essential for controlled labeling reactions, especially in nucleic acid and diagnostic applications.

2. High Fluorescence Intensity

Strong green emission under blue-light excitation makes it ideal for sensitive fluorescence detection.

Excellent signal-to-noise ratio in imaging and analytical assays.

3. Stable and Water-Soluble

Readily soluble in aqueous buffers.

Chemically stable for storage and compatible with biological environments.

4. Bioconjugation Flexibility

The free carboxyl group allows easy and targeted functionalization using standard coupling reagents.

Forms durable amide linkages, enabling robust performance in harsh assay conditions.

5. Low Toxicity

Suitable for live-cell imaging and in vitro assays, with minimal cytotoxicity at standard working concentrations.

5-Carboxyfluorescein (CAS 76823-03-5) is a highly specific, single-isomer green fluorescent dye used extensively in bioconjugation, microscopy, flow cytometry, and nucleic acid labeling. Its defined molecular structure and reactive carboxyl group enable precise, reproducible labeling of biomolecules, making it ideal for quantitative assays, biological imaging, and diagnostic applications. Compared to isomeric mixtures, 5-carboxyfluorescein ensures greater control and consistency, supporting high-performance results in life sciences research and molecular diagnostics.

Previous

Fluorescein Isothiocyanate丨CAS 27072-45-3

Next

6-Carboxyfluorescein丨CAS 3301-79-9