Description

Disulfo-Cy3 Maleimide is a water-soluble, near-infrared fluorescent labeling reagent designed for the site-specific conjugation of biomolecules. Its core value lies in enabling high-sensitivity detection and imaging through stable thioether bond formation with free sulfhydryl (-SH) groups. This compound is essential for researchers and manufacturers in bioconjugation, bioimaging, and diagnostic assay development, particularly where aqueous solubility and reduced dye aggregation are critical.

Application

• Antibody-Drug Conjugate (ADC) Development: Site-specific labeling of engineered cysteine residues on monoclonal antibodies for targeted therapy and payload tracking.
• Protein & Peptide Labeling: Fluorescent tagging of cysteine-containing proteins for studies in protein-protein interactions, cellular localization, and purification monitoring.
• Oligonucleotide Probes: Conjugation to thiol-modified DNA or RNA for fluorescence in situ hybridization (FISH) and real-time PCR applications.
• Live-Cell Imaging: Labeling of cell surface proteins or intracellular targets for dynamic, long-term imaging with minimal background interference.
• Diagnostic Assays: Development of fluorescent lateral flow assays (LFAs) and ELISA kits for high-sensitivity detection of biomarkers.
• Nanoparticle Functionalization: Conjugation to gold nanoparticles, liposomes, or other nanocarriers for theranostic (therapy + diagnostic) applications.

Basic Information

Item	Details
Product Name	Disulfo-Cy3 Maleimide
CAS No.	1656990-68-9
Molecular Formula	C37H41KN2O11S2 (Potassium salt form)
Molecular Weight	817.0 g/mol (approx.)
Synonyms	Sulfo-Cyanine3 Maleimide; Cy3 Maleimide, Disulfonated; 2,5-Dioxopyrrolidin-1-yl 3-(2-((1E,3E)-5-((E)-1-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-3-sulfonatoprop-1-en-2-yl)-3,3-dimethyl-5-sulfo-1-(3-sulfonatopropyl)indolin-2-ylidene)penta-1,3-dien-1-yl)-1-ethyl-3,3-dimethyl-3H-indol-1-ium-5-sulfonate; Maleimide-Cy3, Disulfo; Water-soluble Cy3 Maleimide; Sulfo-Cy3 Maleimide, Potassium Salt
EINECS	Contact for details

Quality Control

Our Disulfo-Cy3 Maleimide is manufactured under strict quality management systems. Each batch undergoes rigorous analytical testing, including HPLC for purity, mass spectrometry for identity confirmation, and spectrophotometry for dye performance. A comprehensive Certificate of Analysis (COA) detailing purity, absorbance/emission profiles, and functional performance is provided with every shipment to ensure consistency for your critical research and development.

Storage

Preserve in a tightly closed container, protected from light. Store desiccated at -20°C or below for long-term stability. This product is hygroscopic (moisture-sensitive). Allow the vial to equilibrate to room temperature in a desiccator before opening to prevent condensation and hydrolysis.

Specification

Item	Specification
Appearance	Dark red to purple solid
Identification (HPLC/MS)	Conforms to structure
Purity (HPLC)	≥ 95.0%
Absorption Maximum (λmax)	548 - 554 nm
Emission Maximum	562 - 568 nm
Extinction Coefficient (ε)	≥ 150,000 cm⁻¹M⁻¹
Solubility	Freely soluble in water, DMSO, PBS
Single Isomer Content (HPLC)	Contact for details
Free Maleimide (Assay)	≥ 90%
Water Content (KF)	≤ 5.0%

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