Description

n-(Azide-PEG3)-N'-(Mal-PEG4)-Cy5 is a heterobifunctional, near-infrared fluorescent labeling and crosslinking reagent designed for advanced bioconjugation. This compound matters for researchers and developers requiring precise, site-specific attachment of fluorophores or other functional groups to biomolecules like proteins, antibodies, or oligonucleotides. It is essential for professionals in biopharmaceutical R&D, diagnostic assay development, and advanced materials science who need to create stable, fluorescently tagged conjugates for imaging, tracking, and detection applications.

Application

• Site-Specific Bioconjugation: Enables controlled, covalent attachment of near-infrared Cy5 fluorophores to thiol-containing biomolecules via the maleimide (Mal) group, while the azide (N3) group allows for subsequent click chemistry modifications.
• Fluorescent Labeling of Proteins & Antibodies: Used to create brightly labeled protein and antibody conjugates for fluorescence microscopy, flow cytometry (FACS), and in vivo imaging applications, leveraging the deep tissue penetration of Cy5 emission.
• Development of Diagnostic Probes & Assays: Serves as a key building block for constructing fluorescent probes, biosensors, and components for immunoassays (e.g., ELISA) and lateral flow tests.
• Polymer & Materials Functionalization: Facilitates the introduction of fluorescent and clickable handles onto surfaces, nanoparticles, hydrogels, and other polymeric materials for tracking and further chemical modification.
• Chemical Biology & Proteomics Research: A valuable tool for studying biomolecular interactions, cellular uptake, and trafficking pathways using fluorescence-based techniques.
• ADC (Antibody-Drug Conjugate) & Therapeutic Agent Development: Can be utilized in the research phase for constructing and optimizing linker-payload systems in targeted therapeutics.

Basic Information

Product Name	n-(Azide-PEG3)-N'-(Mal-PEG4)-Cy5
CAS No.	2107273-74-3
Molecular Formula	C58H78N8O15S22- • 2 Counterion+
Molecular Weight	~1151.4 (Free acid form, excluding counterions)
Synonyms	Cy5 azide-PEG3-maleimide-PEG4; Maleimide-PEG4-azide-PEG3-Cy5; Azido-PEG3-Cy5-Mal-PEG4; N3-PEG3-Cy5-PEG4-Mal; Cy5-PEG3-azide-PEG4-maleimide; Sulfo-Cy5 azide-PEG3-maleimide-PEG4 (common trade name style); 1-{3-[2-{2-[2-(2-{3-[(2,5-Dioxo-2,5-dihydro-1H-pyrrol-1-yl)methoxy]ethoxy}ethoxy)ethoxy]ethoxy}ethoxy]propyl}-1H-1,2,3-triazol-4-yl}methyl 2-{[(1E,3E)-5-{1,1-dimethyl-3-[4-(sulfonatomethyl)phenyl]-2-[(1E,3E,5E)-5-(1,1,3-trimethyl-1,3-dihydro-2H-benz[e]indol-2-ylidene)penta-1,3-dien-1-yl]-1H-indol-3-ium-2-yl}penta-1,3-dien-1-yl]-1,1-dimethyl-1H-benz[e]indol-3-ium-3-yl}ethanesulfonate
EINECS	Contact for details

Quality Control

Our n-(Azide-PEG3)-N'-(Mal-PEG4)-Cy5 is manufactured under strict quality protocols to ensure batch-to-batch consistency and performance. Each lot undergoes comprehensive analytical testing, including HPLC for purity, mass spectrometry (MS) for identity confirmation, and NMR for structural verification. Certificates of Analysis (COA) detailing all specifications and test results are provided with every shipment to support your research and regulatory documentation needs.

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 before opening to minimize condensation and moisture uptake. Under these conditions, the product is typically stable for at least 24 months from the date of receipt.

Specification

Item	Specification
Appearance	Dark blue to green solid or film
Identification (HPLC-MS)	Conforms to structure
Purity (HPLC)	≥ 95%
Extinction Coefficient (ε)	~250,000 L·mol⁻¹·cm⁻¹ (at λmax ~649 nm in aqueous buffer)
Fluorescence Emission (λmax)	~670 nm
Water Content (KF)	≤ 5.0 %
Functional Group Integrity	Azide & Maleimide groups active by assay

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