5(6)-Carboxyfluorescein

Synonym(s):5(6)-Carboxyfluorescein;5(6)-FAM;5,6-CF

CAS NO.：72088-94-9
Empirical Formula: C42H24O14
Molecular Weight: 752.63
MDL number: MFCD00151081
EINECS: 276-331-1
SAFETY DATA SHEET (SDS)
Update Date: 2026-01-15 11:31:18

What is 5(6)-Carboxyfluorescein?

Description

5(6)-Carboxyfluorescein is a mixture of 5-carboxy and 6-carboxy derivatives of fluorescein. It is commonly used to label biomolecules through a reaction involving the carboxyl group. Unlike its succinimidyl ester derivative CFSE , 5(6)-carboxyfluorescein is membrane impermeant. As a result, it can be used in studies of membrane permeability. 5(6)-Carboxyfluorescein displays excellent fluorescence (excitation/emission at 492/514 nm, respectively), and its excitation maximum closely matches the 488 nm spectral line of argon-ion lasers.

Chemical properties

Dark-Orange to Brown Solid

The Uses of 5(6)-Carboxyfluorescein

A popular probe of determination of intracellular pH.

The Uses of 5(6)-Carboxyfluorescein

5(6)-FAM, A useful reagent for the preparation of hydrolytically stable fluorescent conjugates and is a useful starting material for the synthesis of other fluorescein-derives reagent.

The Uses of 5(6)-Carboxyfluorescein

As a popular probe of determination of intracellular pH, 5(6)-Carboxyfluoresceincan be used as useful reagent for the preparation of hydrolytically stable fluorescent conjugates and a useful starting material for the synthesis of other fluorescein-derives reagent

What are the applications of Application

5(6)-Carboxyfluorescein is used in the preparation of fluorescent peptide and protein conjugates

What are the applications of Application

5(6)-carboxyfluorescein, mixed isomers is a pH indicator

Definition

ChEBI: 5(6)-carboxyfluorescein is a commercially available mixture of 5-carboxyfluorescein and 6-carboxyfluorescein isomers. A fluorescent dye, it is commonly used as a tracer agent. It has a role as a tracer and a fluorescent dye. It contains a 5-carboxyfluorescein and a 6-carboxyfluorescein.

Solubility in organics

5(6)-Carboxyfluorescein is soluble in organic solvents such as ethanol, DMSO, and dimethyl formamide. The solubility of 5(6)-carboxyfluorescein in these solvents is approximately 5, 0.5, and 1 mg/ml, respectively.

Properties of 5(6)-Carboxyfluorescein

Melting point:	275 °C
Boiling point:	464.9°C (rough estimate)
Density	1.3418 (rough estimate)
refractive index	1.6380 (estimate)
storage temp.	Keep in dark place,Inert atmosphere,Room temperature
solubility	DMSO (Sparingly), Methanol (Slightly, Heated)
form	Solid
color	Light Yellow to Dark Brown
Water Solubility	slightly soluble
EPA Substance Registry System	Spiro[isobenzofuran-1(3H),9'-[9H]xanthene]-ar-carboxylic acid, 3',6'-dihydroxy-3-oxo- (72088-94-9)

Safety information for 5(6)-Carboxyfluorescein

Signal word	Warning
Pictogram(s)	Exclamation Mark Irritant GHS07
GHS Hazard Statements	H319:Serious eye damage/eye irritation
Precautionary Statement Codes	P305+P351+P338:IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

Computed Descriptors for 5(6)-Carboxyfluorescein

InChIKey	CPRVUBZYHZGASQ-UHFFFAOYSA-N
SMILES	C12(OC(=O)C3C=CC(C(=O)O)=CC1=3)C1=CC=C(O)C=C1OC1C=C(O)C=CC2=1.C12(OC(=O)C3C=C(C(=O)O)C=CC1=3)C1=CC=C(O)C=C1OC1C=C(O)C=CC2=1