Description

Cyanine 3 Monofunctional Hexanoic Acid Dye, Potassium Salt is a reactive near-infrared fluorescent labeling agent designed for the covalent conjugation of biomolecules. This compound matters for its excellent photostability, high molar absorptivity, and water solubility, which are critical for generating bright, stable signals in demanding assays. Researchers and developers in the fields of molecular diagnostics, flow cytometry, and in vivo imaging rely on this dye for its reliable performance and single-point attachment chemistry, which minimizes labeling-induced interference.

Application

• Nucleic Acid Labeling: Covalent attachment to oligonucleotide probes for fluorescence in situ hybridization (FISH), qPCR, and microarray applications.
• Antibody & Protein Conjugation: Site-specific labeling of monoclonal antibodies, proteins, and peptides for use in immunofluorescence, Western blotting, and immunohistochemistry.
• Flow Cytometry & Cell Analysis: Preparation of fluorescently-tagged antibodies and other ligands for high-throughput cell sorting and phenotyping.
• In Vivo & Small Animal Imaging: Conjugation to targeting molecules (e.g., peptides, antibodies) for non-invasive optical imaging studies.
• Biomaterial & Nanoparticle Functionalization: Incorporation into polymers, hydrogels, and nanoparticle surfaces to create fluorescently traceable materials.
• Microscopy & Super-Resolution Imaging: Used as a bright, photostable fluorophore for confocal, TIRF, and STORM/PALM microscopy techniques.

Basic Information

Product Name	Cyanine 3 Monofunctional Hexanoic Acid Dye, Potassium Salt
CAS No.	449175-57-9
Molecular Formula	C37H45KN2O4S2
Molecular Weight	708.99 g/mol
Synonyms	Cy3 Hexanoic Acid, Potassium Salt; Cy3 Monofunctional NHS Ester (potassium salt precursor); Sulfo-Cyanine3 carboxylic acid, potassium salt; 1-(5-Carboxypentyl)-2-((1E,3E)-3-(1-(5-carboxypentyl)-3,3-dimethyl-5-sulfoindolin-2-ylidene)prop-1-en-1-yl)-3,3-dimethyl-3H-indol-1-ium-5-sulfonate, potassium salt; Cy3™ dye acid; Cy3 SE (acid form); Potassium 2-((1E,3E)-3-(1-(6-carboxyhexyl)-3,3-dimethyl-5-sulfo-2,3-dihydro-1H-indol-2-ylidene)prop-1-en-1-yl)-1-(6-carboxyhexyl)-3,3-dimethyl-3H-indol-1-ium-5-sulfonate
EINECS	Contact for details

Quality Control

Our Cyanine 3 Monofunctional Hexanoic Acid Dye, Potassium Salt is manufactured under strict quality management systems. Each batch undergoes rigorous analytical testing, including HPLC for purity, NMR for structural confirmation, and mass spectrometry for identity verification, to ensure consistent performance and batch-to-batch reproducibility. Certificates of Analysis (COA) detailing spectral properties (absorbance/fluorescence maxima, extinction coefficient) and purity data are provided with every shipment.

Storage

Preserve in a tightly closed container, protected from light. For long-term stability, store desiccated at -20°C. Under these conditions, the product is typically stable for at least 24 months. Allow the vial to equilibrate to room temperature in a desiccator before opening to prevent condensation and moisture uptake.

Specification

Item	Specification
Appearance	Dark green to purple solid
Identification (HPLC)	Retention time corresponds to reference standard
Identification (MS)	Consistent with molecular weight
Purity (HPLC)	≥ 95.0%
Water Content (KF)	≤ 5.0%
Absorption Maximum (λmax)	548 - 552 nm
Emission Maximum (λem)	562 - 568 nm
Extinction Coefficient (ε)	≥ 150,000 cm⁻¹M⁻¹

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