Fluorescein 6-isothiocyanate (isomer II)
Also known as: 6-FITC, 6-Isothiocyanatofluorescein, FITC isomer II, Fluorescein 6-isothiocyanate isomer II, Fluorescein 6-isothiocyanate, 3',6'-dihydroxy-6-isothiocyanato-3H-spiro[2-benzofuran-1,9'-xanthen]-3-one, FITC 'ISOMER II', FLUORESCEIN 6-ISOTHIOCYANATE, ISOMER 2, FLUORESCEIN ISOTHIOCYANATE (ISOMER II)
Fluorescein 6-isothiocyanate (isomer II) (CAS 18861-78-4) is a compound in the Organic Acids category listed in the Jingsj chemical database. It has the molecular formula C21H11NO5S and a molecular weight of 389.381 g/mol. Key properties include a boiling point of 719.1±60.0 °C at 760 mmHg, a density of 1.5±0.1 g/cm3 and a flash point of 388.7±32.9 °C. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.
- CAS No.
- 18861-78-4
- Jingsj CID
- J-1960812-9
- Molecular Formula
- C21H11NO5S
- Molecular Weight
- 389.381 g/mol
- Category
- Organic Acids
- Last updated
- 8/21/2026
No offers for this compound yet.
Request a quotePhysicochemical Properties
| Boiling Point | 719.1±60.0 °C at 760 mmHg |
|---|---|
| Density | 1.5±0.1 g/cm3 |
| Flash Point | 388.7±32.9 °C |
| Exact Mass | 389.035797 |
| PSA | 120.44000 |
| LogP | 4.00 |
| Vapor Pressure | 0.0±2.4 mmHg at 25°C |
| Refractive Index | 1.754 |
Activity & Biological Data
| Target | Kd: 8.74 (N-Acetyl-L-Lysine), 2.72 (normal mouse IgG), 1.88 (4-4-20)[1] |
|---|---|
| Additional Information | [1]. Swindlehurst CA, et al. Fluorescence measurements of immune complexes of Mab 4-4-20 with isomeric haptens. Biophys J. 1991 Mar;59(3):619-28. |
Customs & Trade Information
| HS Code | 2932999099 |
|---|---|
| Summary | 2932999099. other heterocyclic compounds with oxygen hetero-atom(s) only. VAT:17.0%. Tax rebate rate:13.0%. . MFN tariff:6.5%. General tariff:20.0% |
Frequently Asked Questions
What is the CAS number of Fluorescein 6-isothiocyanate (isomer II)?
The CAS number of Fluorescein 6-isothiocyanate (isomer II) is 18861-78-4.
What are the molecular formula and molecular weight of Fluorescein 6-isothiocyanate (isomer II)?
Fluorescein 6-isothiocyanate (isomer II) has molecular formula C21H11NO5S and molecular weight 389.381 g/mol.
What are the upstream and downstream products of Fluorescein 6-isothiocyanate (isomer II)?
For Fluorescein 6-isothiocyanate (isomer II), Upstream Products: Thiophosgene, 6-Aminofluorescein, Resorcinol.
Data compiled from public chemical databases such as PubChem and supplier catalogs; supplier offers are provided by suppliers.
Last updated:
How to cite: Jingsj. "Fluorescein 6-isothiocyanate (isomer II) (CAS 18861-78-4)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-1960812-9 (accessed 2026-11-09).
Data for reference only; verify product details with suppliers before purchase.