Molekula
Fluorescein disodium salt (insoluble, 50-53% dye content)
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 2000 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
Fluorescein disodium salt (insoluble, 50–53% dye content) is a fluorescent dye used in biological staining, diagnostic assays, and tracer studies. It exhibits strong green fluorescence when excited by blue light. Available in powder form with a molecular formula of C20H10Na2O5, molecular weight of 376.28 g/mol, and CAS number 518-47-8. Stable at ambient temperature and suitable for applications requiring high purity and consistent performance. Molekula supplies Fluorescein disodium salt (insoluble, 50–53% dye content) from research to bulk quantities with full documentation and ISO 9001:2015 traceability.
Example image for illustration only. Other packaging and pack sizes are available.
Pricing & pack sizes
These pack sizes aren't a limit. Molekula manufactures, sources and repacks to order — if you need 500 kg and only see 1 kg listed, . We quote from grams to multi-tonne.
Need a different size? Add the nearest pack and change the size in your basket — we price it at the same rate per unit.
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500 g — £62.00 per pack ex VAT · £74.40 inc. VAT
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Tell us how much you need and when — drums, IBCs, sacks or a one-off bulk lot. We'll manufacture or source it and come back with a price.
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Specifications
| Property | Value |
|---|---|
| Appearance | Red/ dark orange powder |
| Heavy metals | ≤ 40 mg/kg |
| Loss on Drying | ≤ 8% |
| Assay | ≥80.0% |
| Absorption Ratio | 1.20-1.70 ((λmax - 15 nm)/(λmax +15 nm)) |
| Cadmium (Cd) | ≤ 1 mg/kg |
| Lead (Pb) | ≤ 10 mg/kg |
| Mercury (Hg) | ≤ 1 mg/kg |
| Arsenic (As) | ≤ 3 mg/kg |
| Wavelength of Max. Absorption | 488.0 - 492.0 nm (in distilled water) |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Flash Point | 218 °C |
| Acidity | Neutral |
Identification
| Property | Value |
|---|---|
| SKU | 15462696 |
| CAS Number | 518-47-8 |
| IUPAC Name | disodium;2-(3-oxido-6-oxoxanthen-9-yl)benzoate |
| EC Number | 208-253-0 |
| Molecular Formula | C20H10Na2O5 |
| Molecular Weight | 376.28 |
| Exact Mass | 376.0324 |
| SMILES | C1=CC=C(C(=C1)C2=C3C=CC(=O)C=C3OC4=C2C=CC(=C4)[O-])C(=O)[O-].[Na+].[Na+] |
| InChIKey | NJDNXYGOVLYJHP-UHFFFAOYSA-L |
| InChI | InChI=1S/C20H12O5.2Na/c21-11-5-7-15-17(9-11)25-18-10-12(22)6-8-16(18)19(15)13-3-1-2-4-14(13)20(23)24;;/h1-10,21H,(H,23,24);;/q;2*+1/p-2 |
| PubChem CID | 10608 |
| REACH Code | Y113 |
| TSCA Listed | Yes |
| HTS Code | 32129000 |
| Tariff Code | 3212900000 |
Safety & GHS
Precautionary statements
- P264 Wash thoroughly after handling
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P308+313 IF exposed or concerned: Get medical advice/attention
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Portuguese, Spanish.
Certificate of Analysis (CoA) by batch
Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.
Synonyms
- Ak-Fluor
- Fluorescein disodium salt
- Fluorescein, soluble
- Ki202
- Resorcinol phthalein sodium
- Sodium fluorescein
- Soluble fluorescein
- Uranin
- Uranine WSS
- Uranine Yellow
Frequently asked questions
What is Fluorescein disodium salt used for?
It is primarily used as a fluorescent tracer in biological and environmental studies, including flow cytometry, microscopy, and water tracing applications.
What is the chemical formula and molecular weight?
The formula is C20H10Na2O5 with a molecular weight of 376.28 g/mol.
How should Fluorescein disodium salt be stored?
It should be stored at ambient temperature, protected from moisture and light.
What grade is available?
This product is available as a technical grade with 50–53% dye content, suitable for research and industrial applications.
Can Molekula supply this in bulk?
Yes, Molekula can supply Fluorescein disodium salt in bulk quantities—please contact our sales team for pricing and availability.
What documentation comes with the order?
Each order includes a Certificate of Analysis (CoA) and safety data sheet (SDS); additional documentation can be provided upon request.
Ready to order or need a custom pack?
Tell us the product, grade, and quantity — Molekula usually responds within one working day with pricing and lead time.