Description

Cy5.5 Alkyne is a near-infrared fluorescent labeling reagent featuring a terminal alkyne group for bioorthogonal click chemistry conjugation. This compound is essential for researchers and developers requiring high-sensitivity, low-background labeling of biomolecules in complex biological systems. It is primarily used by professionals in bioconjugation, pharmaceutical R&D, and in vitro diagnostics for creating targeted imaging probes and therapeutic agents.

Application

• Bioorthogonal Labeling: Conjugation to azide-modified biomolecules (proteins, antibodies, oligonucleotides, glycans) via copper-catalyzed or strain-promoted azide-alkyne cycloaddition (CuAAC/SPAAC).
• In Vivo & In Vitro Imaging: Synthesis of near-infrared (NIR) fluorescent probes for deep-tissue imaging, tumor targeting, and cellular tracking due to its favorable emission wavelength (~695 nm).
• Proteomics & Biomarker Discovery: Labeling of proteins and peptides for gel-based analysis, western blotting, and fluorescence-based detection assays.
• Diagnostic Reagent Development: Manufacturing of fluorescent conjugates for lateral flow assays, ELISA, and other point-of-care diagnostic platforms.
• Drug Delivery & Therapeutics: Conjugation to drug molecules, nanoparticles, or targeting ligands for theranostic applications.
• Flow Cytometry & Microscopy: Preparation of fluorescent antibodies or other detection reagents for cell sorting and high-resolution imaging.

Basic Information

Product Name	Cy5.5 Alkyne
CAS No.	1628790-37-3
Molecular Formula	C38H45KN2O8S2
Molecular Weight	760.99 g/mol
Synonyms	Sulfo-Cyanine5.5 alkyne; Cy5.5® Alkyne; 1-(6-((2,5-Dioxopyrrolidin-1-yl)oxy)-6-oxohexyl)-2-((1E,3E)-5-((E)-1-(5-carboxypentyl)-3,3-dimethyl-5-sulfoindolin-2-ylidene)penta-1,3-dien-1-yl)-3,3-dimethyl-3H-indol-1-ium-5-sulfonate potassium salt; NIR dye alkyne; Near-infrared fluorescent alkyne; Potassium 1-(6-((2,5-dioxopyrrolidin-1-yl)oxy)-6-oxohexyl)-2-((1E,3E)-5-((E)-1-(5-carboxypentyl)-3,3-dimethyl-5-sulfoindolin-2-ylidene)penta-1,3-dien-1-yl)-3,3-dimethyl-3H-indol-1-ium-5-sulfonate
EINECS	Contact for details

Quality Control

Our Cy5.5 Alkyne is manufactured under strict quality management systems. Each batch undergoes rigorous analytical testing to ensure high purity and consistent performance for sensitive research and diagnostic applications. A comprehensive Certificate of Analysis (COA) detailing purity, identity, and functional performance is provided with every shipment.

Storage

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

Specification

Item	Specification
Appearance	Dark green to blue solid
Identification (HPLC/MS)	Conforms to structure
Purity (HPLC)	≥ 95% (Area %)
Absorption (λmax)	~ 675 nm
Emission (λmax)	~ 695 nm
Extinction Coefficient (ε)	≥ 190,000 cm⁻¹M⁻¹
Water Content (KF)	≤ 5.0 %
Functional Performance	Conjugation efficiency ≥ 90% (by HPLC)

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