Molekula
5-Fluorescein isothiocyanate isomer I (FITC)
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
5-Fluorescein isothiocyanate isomer I (FITC) is a fluorescent dye used in bioconjugation for labeling proteins, antibodies, and other biomolecules in research and diagnostics. It exhibits strong fluorescence when excited by blue light. Available with CAS number 3326-32-7, molecular formula C21H11NO5S, and molecular weight 389.38 g/mol. Store at 2 to 8 °C. Hazard symbol: Danger. Molekula supplies FITC isomer I 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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100 mg — £60.00 per pack ex VAT · £72.00 inc. VAT
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1 g — £149.60 per pack ex VAT · £179.52 inc. VAT
Need a different quantity or pack?
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.
Prices exclude VAT/sales tax and shipping.
Specifications
| Property | Value |
|---|---|
| Appearance | White to Yellow to Orange powder |
| Identification | Conforms to structure |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | 2 to 8 °C |
| Flash Point | 383 °C |
| Acidity | Neutral |
For research use only. Not for human use.
Identification
| Property | Value |
|---|---|
| SKU | 43825432 |
| CAS Number | 3326-32-7 |
| IUPAC Name | 3',6'-dihydroxy-6-isothiocyanatospiro[2-benzofuran-3,9'-xanthene]-1-one |
| EC Number | 222-042-0 |
| Molecular Formula | C21H11NO5S |
| Molecular Weight | 389.38 |
| Exact Mass | 389.0358 |
| SMILES | C1=CC2=C(C=C1N=C=S)C(=O)OC23C4=C(C=C(C=C4)O)OC5=C3C=CC(=C5)O |
| InChIKey | MHMNJMPURVTYEJ-UHFFFAOYSA-N |
| InChI | InChI=1S/C21H11NO5S/c23-12-2-5-16-18(8-12)26-19-9-13(24)3-6-17(19)21(16)15-4-1-11(22-10-28)7-14(15)20(25)27-21/h1-9,23-24H |
| PubChem CID | 18730 |
| REACH Code | Y113 |
| TSCA Listed | Yes |
| HTS Code | 3204900000 |
| Tariff Code | 3204900090 |
Safety & GHS
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Health Hazard
GHS07
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Serious Health Hazard
GHS08
Hazard statements
- H315 Causes skin irritation
- H317 May cause an allergic skin reaction
- H319 Causes serious eye irritation
- H334 May cause allergy or asthma symptoms or breathing difficulties if inhaled
- H335 May cause respiratory irritation
Precautionary statements
- P260 Do not breathe dust/fume/gas/mist/vapours/spray
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P302+352 IF ON SKIN: Wash with soap and water
- P304+340 IF INHALED: Remove victim to fresh air and keep at rest in a position comfortable for breathing
- P305+351+338 IF IN EYES: Rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing
- P308+313 IF exposed or concerned: Get medical advice/attention
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Portuguese, Russian, 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
- 3',6'-dihydroxy-5-isothiocyanato-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one
- 3',6'-dihydroxy-6-isothiocyanatospiro[2-benzofuran-3,9'-xanthene]-1-one
- 5-FITC
- 5-isothiocyanatofluorescein
- FITC
- Fluorescein 5 isothiocyanate Hydrochloride
- fluorescein isothiocyanate isomer 1
- Fluorescein isothiocyanate isomer I
- FLUORESCEIN-5-ISOTHIOCYANATE
- Hydrochloride, Fluorescein-5-isothiocyanate
Frequently asked questions
What is 5-Fluorescein isothiocyanate isomer I (FITC) used for?
FITC is primarily used for labeling proteins, antibodies, and other biomolecules in fluorescence microscopy, flow cytometry, and immunoassays due to its strong fluorescent properties.
What is the chemical formula and molecular weight of FITC?
The formula is C21H11NO5S with a molecular weight of 389.38 g/mol.
How should FITC be stored?
FITC should be stored at 2 to 8 °C in the dark to maintain stability and prevent degradation.
What grade of FITC does Molekula supply?
Molekula supplies FITC in high-purity research grade, suitable for laboratory use.
Can Molekula supply FITC in bulk quantities?
Yes, Molekula can supply FITC in bulk quantities—please contact our sales team for pricing and availability.
What documentation comes with a FITC order?
Each order includes a Certificate of Analysis (CoA) and Safety Data Sheet (SDS) for compliance and safety.
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.