Description

Cyanine5 Carboxylic Acid CAS NO 195867-59-5 is a near-infrared fluorescent dye derivative featuring a reactive carboxylic acid group, enabling covalent conjugation to biomolecules. This compound is critical for creating highly sensitive and stable fluorescent probes for advanced detection and imaging applications. It is primarily needed by researchers and manufacturers in the life sciences, diagnostics, and pharmaceutical development sectors.

Application

• Fluorescent Labeling of Biomolecules: Conjugation to antibodies, peptides, proteins, and oligonucleotides for use in immunoassays (e.g., ELISA, Western Blot) and fluorescence in situ hybridization (FISH).
• Bioimaging and Diagnostics: Synthesis of probes for in vivo and in vitro imaging, including tumor targeting, cell tracking, and molecular diagnostics due to its deep tissue penetration and low background fluorescence.
• Flow Cytometry and Cell Analysis: Development of fluorescent tags for cell surface marker staining and intracellular target detection in flow cytometry and high-content screening.
• Polymer and Material Science: Incorporation into functional polymers, nanoparticles, and dendrimers to create smart materials with optical reporting capabilities.
• Drug Delivery and Pharmacokinetics: Labeling of drug candidates, liposomes, or nanocarriers to study their distribution, uptake, and clearance in biological systems.
• Biomolecular Interaction Studies: Use in fluorescence resonance energy transfer (FRET) pairs and other proximity-based assays to study protein-protein interactions and conformational changes.

Basic Information

Product Name	Cyanine5 Carboxylic Acid
CAS No.	195867-59-5
Molecular Formula	C37H41N2O2+
Molecular Weight	545.74 g/mol
Synonyms	Cy5 Carboxylic Acid; Cy5-COOH; Sulfo-Cyanine5 carboxylic acid (note: often confused, but distinct); 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 (common structural description); Cy™5 carboxylic acid; NIR dye carboxylic acid; Pentamethine cyanine dye carboxylic acid; CAS 195867-59-5
EINECS	Contact for details

Quality Control

Our Cyanine5 Carboxylic Acid is produced under strict quality management systems. Each batch undergoes comprehensive analytical testing, including HPLC for purity, NMR and MS for structural confirmation, and spectrophotometry to verify optical properties. Certificates of Analysis (COA) detailing all specifications are provided to ensure traceability and batch-to-batch consistency for your critical research and manufacturing needs.

Storage

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

Specification

Item	Specification
Appearance	Dark blue to green solid
Identification (HPLC)	Retention time corresponds to reference standard
Identification (MS)	Consistent with molecular ion [M]+
Purity (HPLC)	≥95.0% (Area %)
Absorption Maximum (λmax)	646 - 652 nm
Emission Maximum (λem)	662 - 668 nm
Extinction Coefficient (ε)	≥ 200,000 L·mol⁻¹·cm⁻¹
Water Content (KF)	≤ 5.0 %

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