Description

Fluorescein-5(6)-Carboxamidocaproic Acid is a reactive, amine-reactive derivative of fluorescein, featuring a 6-carbon spacer arm terminating in a carboxylic acid group. This bifunctional design is critical for creating stable, fluorescent conjugates with primary amines, such as those on proteins, peptides, and other biomolecules, without significantly altering their biological activity. It is an essential tool for researchers and manufacturers in the life sciences, diagnostics, and biotechnology sectors who require high-sensitivity fluorescent labeling for applications like immunoassays, flow cytometry, and fluorescence microscopy.

Application

• Bioconjugation and Protein Labeling: Primary application for covalently attaching a bright, photostable fluorescent tag to antibodies, enzymes, and other proteins via their lysine residues.
• Diagnostic Assay Development: Used to create fluorescent probes and tracers for ELISA, lateral flow assays, and other in vitro diagnostic (IVD) kits.
• Cell Biology and Imaging: Preparation of fluorescent ligands or substrates for live-cell imaging, receptor tracking, and intracellular process visualization.
• Flow Cytometry Reagents: Synthesis of antibody-fluorophore conjugates for multicolor flow cytometry analysis of cell surface markers.
• Biomaterial and Nanoparticle Functionalization: Labeling of polymers, dendrimers, or nanoparticles to create traceable delivery systems or imaging agents.
• Peptide Synthesis and Modification: Incorporation of a fluorescent label during solid-phase peptide synthesis or post-synthetic modification for peptide-based research.

Basic Information

Item	Detail
Product Name	Fluorescein-5(6)-Carboxamidocaproic Acid
CAS No.	265981-56-4
Molecular Formula	C30H28N2O8
Molecular Weight	544.55 g/mol
Synonyms	5(6)-FAM-X, SE; 6-(Fluorescein-5(6)-carboxamido)hexanoic Acid; 5(6)-Carboxyfluorescein-X, SE; FAM-X, SE; Fluorescein-X, SE; 6-[(5(6)-Carboxyfluorescein)amino]hexanoic Acid; Succinimidyl Ester of 6-((Fluorescein-5-carboxamido)hexanoic Acid) (mixed isomers); 5(6)-FAM, SE
EINECS	Contact for details

Quality Control

Every batch of Fluorescein-5(6)-Carboxamidocaproic Acid is manufactured and tested under strict quality management systems. We provide comprehensive analytical data to ensure product integrity, including verification of identity, purity, and functional performance. A detailed Certificate of Analysis (COA) is supplied with each shipment, documenting key parameters such as HPLC purity, extinction coefficient, and functional group activity. Our quality commitment supports applications requiring reproducible and reliable bioconjugation results.

Storage

Preserve in a tightly closed container, protected from light. For long-term stability, store desiccated at -20°C or below. Allow the vial to equilibrate to room temperature in a desiccator before opening to prevent condensation and hydrolysis of the active ester. The product is light-sensitive (store away from light).

Specification

Item	Specification
Appearance	Orange to red powder
Identification (HPLC)	Conforms
Purity (HPLC)	≥95% (typical)
Extinction Coefficient (ε)	~68,000 cm⁻¹M⁻¹ at 492 nm (pH ≥9)
Fluorescence Emission	~515 nm (pH ≥9)
Solubility	DMSO, DMF
Water Content (KF)	<1.0%

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