6-Carboxyfluorescein
6-Carboxyfluorescein (CAS 3301-79-9), with the empirical formula C21H12O7 and a molecular weight of 376.32 g/mol, is a fluorescent dye utilized as a labelling agent. It is an important compound in biochemical research and cell biology for its luminescent properties. This reagent is employed in various diagnostic and research applications requiring fluorescent detection.
- IUPAC
- 6-FAM,FLUOS

Fluorescent Labelling
6-Carboxyfluorescein serves as a fluorescent label, emitting light at specific wavelengths after excitation. It is commonly used to tag biomolecules for detection in various biological assays and imaging techniques.
Cell Biology Research
This compound finds application in cell biology for tracking cellular processes and localisation of molecules. Its fluorescent properties allow for visualisation within biological systems, aiding in the study of cellular function.
Fluorescent Probes
As a derivative of fluorescein, it functions as a fluorescent probe, enabling researchers to detect and quantify substances or processes. Its spectral characteristics are suitable for a range of analytical methods.
| Molecular weight | 376.32 |
|---|---|
| Empirical formula | C21H12O7 |
| Assay | ~97% (HPLC) |
| Storage temperature | 2-8°C |
| Application | Fluorescent dye. |
| Melting point | >300 °C(lit.) |

Hazard statements
- H315Causes skin irritation
- H319Causes serious eye irritation
- H335May cause respiratory irritation
Precautionary statements
- P261Avoid breathing dust, fume, gas or vapours
- P305IF IN EYES
| Protective equipment | dust mask type N95 (US), Eyeshields, Gloves |
|---|---|
| Water hazard class (WGK, DE) | 3 |
| Hazard codes (EU) | Xi |
| Risk statements (R) | 36/37/38 |
| Safety statements (S) | 26-36/37 |
Hazard information is provided for guidance. Always consult the product Safety Data Sheet (SDS), available on request, before handling.
| Absorption | λmax 492 nm, 0.1 N in NaOH |
|---|---|
| Fluorescence | λex 492 nm; λem 517 nm (pH 8.0) |
Documentation
Every batch ships with a Certificate of Analysis covering assay, identity and purity; the grade is confirmed against your enquiry. Safety Data Sheets and technical data sheets are available on request.
Supply & logistics
Samples for technical evaluation; bulk MOQ by grade and packaging. In-stock material ships in 7–10 working days, worldwide, with full export documentation.
What is 6-Carboxyfluorescein used for?
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6-Carboxyfluorescein is primarily used as a fluorescent dye for labelling applications in biochemical research, cell biology, and as a fluorescent probe in various analytical techniques.
What are the CAS number and formula for 6-Carboxyfluorescein?
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The CAS number for 6-Carboxyfluorescein is 3301-79-9, and its empirical formula is C21H12O7.
What grade and purity does Tech Serve Solutions supply?
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Tech Serve Solutions supplies 6-Carboxyfluorescein with an assay of ~97% (HPLC). We do not represent this product as USP, BP, or EP grade.
How should 6-Carboxyfluorescein be handled safely?
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Handle 6-Carboxyfluorescein with appropriate personal protective equipment, including a dust mask type N95 (US), eyeshields, and gloves, as it may cause skin irritation (H315), eye irritation (H319), and respiratory irritation (H335).
Is 6-Carboxyfluorescein available for export and how is it packaged?
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Yes, Tech Serve Solutions exports 6-Carboxyfluorescein globally. It is typically stored at 2-8°C to maintain its stability and efficacy.
How can I request a sample or quote for 6-Carboxyfluorescein?
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To request a sample or a quotation for 6-Carboxyfluorescein, please contact our sales department through the provided channels on the Tech Serve Solutions website.
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