Description

5(6)-Carboxyfluorescein n-Succinimidyl Ester is a high-purity, amine-reactive fluorescent labeling reagent widely used in biochemistry and molecular biology. This compound is critical for creating stable, fluorescently tagged conjugates of proteins, peptides, and other biomolecules for detection and analysis. It is an essential tool for researchers and manufacturers in the fields of diagnostic assay development, flow cytometry, and cellular imaging.

Application

• Protein and Antibody Labeling: Conjugation to primary amines (lysine residues) for fluorescence-activated cell sorting (FACS), immunofluorescence, and Western blotting.
• Diagnostic Assay Development: Used as a key fluorescent tracer or detection reagent in ELISA, lateral flow assays, and other immunoassays.
• Cellular Tracking and Viability Assays: Labeling of cells or biomolecules to monitor uptake, localization, and cytotoxicity.
• Nucleic Acid Probe Labeling: Modification of amine-modified oligonucleotides for fluorescence in situ hybridization (FISH) and real-time PCR applications.
• Bioconjugation and Drug Delivery: Facilitating the attachment of fluorescent markers to nanoparticles, polymers, or drug carriers for tracking and biodistribution studies.
• Enzyme Activity Assays: Development of fluorogenic substrates for monitoring enzymatic activity in high-throughput screening.

Basic Information

Product Name	5(6)-Carboxyfluorescein n-Succinimidyl Ester
CAS No.	117548-22-8
Molecular Formula	C25H15NO9
Molecular Weight	473.39 g/mol
Synonyms	5(6)-FAM, SE; 5(6)-Carboxyfluorescein N-hydroxysuccinimide ester; 6-FAM, SE; CFSE; FAM NHS ester; Fluorescein-5(6)-isothiocyanate isomer mixture; 5-Carboxyfluorescein succinimidyl ester; 6-Carboxyfluorescein succinimidyl ester
EINECS	Contact for details

Quality Control

Our 5(6)-Carboxyfluorescein n-Succinimidyl Ester is manufactured under strict quality control protocols to ensure batch-to-batch consistency and high performance. Each lot is characterized by advanced analytical techniques, including HPLC for purity and NMR for structural confirmation. A comprehensive Certificate of Analysis (COA) detailing purity, identity, and performance data is provided with every shipment.

Storage

Preserve in a tightly closed container, protected from light. Store at -20°C or below under desiccant. The product is hygroscopic (moisture-sensitive) and light-sensitive. Allow the vial to equilibrate to room temperature in a desiccator before opening to minimize moisture uptake.

Specification

Item	Specification
Appearance	Orange to red powder
Identification (HPLC)	Conforms
Identification (NMR)	Conforms
Purity (HPLC)	≥ 95.0%
Single Isomer Content (HPLC)	≥ 90.0% (5- or 6-isomer)
Water Content (KF)	≤ 1.0%
Extinction Coefficient	≥ 68,000 cm⁻¹M⁻¹ at 492 nm
Functional Performance	Conforms to reference in labeling test

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.