Fluorescein
IUPAC: 3',6'-dihydroxyspiro[2-benzofuran-3,9'-xanthene]-1-one
| Formula / Notation | C20H12O5 |
|---|---|
| CAS Number | 2321-07-5 |
| Molecular Weight | 332.3 |
| Melting Point | Decomposes at 554 °F. In sealed tube, melts at 597-601 °F with decomposition (NTP, 1992) |
| Solubility | Insoluble (NTP, 1992) |
| Appearance | Fluorescein appears as yellow amorphous solid or orange-red crystals. Latter have greenish-yellow fluorescence by reflected light. Insoluble in water. Soluble in dilute aqueous bases. Very dilute a... |
| Also Known As | 3',6'-dihydroxyspiro[2-benzofuran-3,9'-xanthene]-1-one; 2321-07-5; Solvent Yellow 94; Resorcinolphthalein; Yellow fluorescein; Fluoresceine; Fluorescein acid; 3,6-Fluorandiol; D&C Yellow No. 7; Japan Yellow 201 |
| Category | Indicators |
What is Fluorescein?
Fluorescein (lactone form) is a xanthene dye that is highly fluorescent, detectable even when present in minute quantities. Used forensically to detect traces of blood, in analytical chemistry as an indicator in silver nitrate titrations and in microscopy. It has a role as a radioopaque medium and a fluorescent dye. It is a polyphenol, a gamma-lactone, a xanthene dye, an oxaspiro compound, an organic heteropentacyclic compound and a member of 2-benzofurans. It is functionally related to a fluorescein (acid form).
Formula & Notation
IUPAC Name: 3',6'-dihydroxyspiro[2-benzofuran-3,9'-xanthene]-1-one
Other Names / Synonyms: 3',6'-dihydroxyspiro[2-benzofuran-3,9'-xanthene]-1-one; 2321-07-5; Solvent Yellow 94; Resorcinolphthalein; Yellow fluorescein; Fluoresceine; Fluorescein acid; 3,6-Fluorandiol; D&C Yellow No. 7; Japan Yellow 201
Properties & Characteristics
Physical Data
| Property | Value |
|---|---|
| Melting Point | Decomposes at 554 °F. In sealed tube, melts at 597-601 °F with decomposition (NTP, 1992) |
| Molecular Weight | 332.3 |
| Solubility | Insoluble (NTP, 1992) |
| Appearance | Fluorescein appears as yellow amorphous solid or orange-red crystals. Latter have greenish-yellow fluorescence by reflected light. Insoluble in water. Soluble in dilute aqueous bases. Very dilute a... |
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
Fluorescein (lactone form) is a xanthene dye that is highly fluorescent, detectable even when present in minute quantities. Used forensically to detect traces of blood, in analytical chemistry as an indicator in silver nitrate titrations and in microscopy. It has a role as a radioopaque medium and a fluorescent dye. It is a polyphenol, a gamma-lactone, a xanthene dye, an oxaspiro compound, an organic heteropentacyclic compound and a member of 2-benzofurans. It is functionally related to a fluorescein (acid form).
Used as a pH indicator in acid-base titrations, analytical chemistry, and chemical education demonstrations.
May be irritant or toxic in concentrated form. Handle with care. Consult SDS before use.
The formula or notation for Fluorescein is: C20H12O5