IR-775 Chloride

IR-775 Chloride is a near-infrared (NIR) cyanine dye with excitation/emission at ~775/810 nm, ideal for deep tissue imaging and phototherapy.

Primary applications:

• In vivo fluorescence imaging: Tumor detection, biodistribution, surgical guidance
• Photothermal therapy: Cancer treatment via NIR light-induced hyperthermia
• Photoacoustic imaging: Deep tissue imaging with ultrasound detection
• Theranostics: Combined diagnostic imaging and therapeutic treatment
• Nanomedicine: Nanoparticle labeling and tracking
• Cellular imaging: Mitochondrial targeting, live-cell microscopy

Why NIR imaging: The 700-950 nm window (NIR-I) offers minimal tissue autofluorescence, reduced light scattering, and deeper penetration compared to visible wavelengths, enabling imaging depths of several millimeters to centimeters.

Unique features: Cationic structure drives mitochondrial accumulation, high photothermal conversion efficiency, photoacoustic signal generation, and inherent tumor-targeting capability.

IR-775 exhibits characteristic near-infrared absorption and emission properties.

Spectroscopic properties:

• Excitation maximum: ~775 nm (in aqueous media)
• Emission maximum: ~810 nm
• Stokes shift: ~35 nm
• Extinction coefficient (ε): ~2.2 × 10⁵ M⁻¹cm⁻¹
• Quantum yield: Moderate in aqueous media

Imaging setup recommendations:

• Excitation filter: 750-780 nm bandpass
• Emission filter: 800-830 nm bandpass or >800 nm longpass
• Laser excitation: 785 nm or 808 nm (for photothermal applications)
• Detection: NIR-sensitive cameras (InGaAs or cooled CCD)

Solvent effects: Spectral properties may shift slightly in different solvents. Always verify λmax in your specific experimental conditions.

ChemContract supplies IR-775 Chloride at 90% dye content, verified by UV-Vis spectroscopy.

Quality control methods:

• UV-Vis spectroscopy: Dye content determination based on molar absorptivity
• HPLC analysis: Purity assessment and impurity profiling
• λmax verification: Confirms characteristic absorption at ~775 nm
• Mass spectrometry: Molecular weight confirmation
• Fluorescence spectroscopy: Emission properties verification

Certificate of Analysis includes:

• Batch number and manufacturing date
• UV-Vis absorption spectrum
• Dye content calculation (90%)
• HPLC chromatogram
• Fluorescence emission spectrum (if applicable)
• Appearance and solubility data
• Storage recommendations

Understanding dye content: 90% dye content means the active fluorescent compound comprises 90% of the total weight, with remaining 10% being counterions, residual solvents, or minor impurities. This is typical for cyanine dye chloride salts.

Proper solution preparation is critical for optimal fluorescence performance.

Stock solution preparation:

• Recommended solvent: DMSO or methanol (1-10 mM)
• Alternative solvents: DMF, ethanol
• Procedure: Dissolve dye in minimal volume of DMSO, vortex, sonicate if needed
• Concentration check: Verify by UV-Vis (using known ε value)
• Storage: Aliquot into small volumes, freeze at -20°C
• Light protection: Wrap tubes in foil

Working solution preparation:

• In vitro (cells): Dilute stock to 0.1-10 µM in cell culture medium
• In vivo (animals): Dilute in PBS or saline to 1-10 mg/kg dosing
• Final DMSO: Keep <0.1% for cell studies, <5% for in vivo
• Prepare fresh: Working solutions should be used promptly

Important notes:

• Protect all solutions from light during preparation and storage
• Avoid freeze-thaw cycles (aliquot stock solutions)
• Cyanine dyes can aggregate at high concentrations – verify by spectroscopy
• For in vivo use, filter sterilize (0.22 µm) if needed

Optimal concentrations vary by application and should be optimized for specific experimental systems.

In vitro cell imaging:

• Concentration: 0.1-10 µM (typical: 1-5 µM)
• Incubation: 15-60 minutes at 37°C
• Washing: 1-2 washes with PBS
• Imaging: Ex 775 nm, Em 810 nm
• Optimization: Test range to balance signal and cytotoxicity

In vivo imaging:

• Injection dose: 1-10 mg/kg body weight (typical: 2-5 mg/kg)
• Route: I.V., I.P., or subcutaneous
• Imaging time: 1-24 hours post-injection (optimize for target)
• Excitation: 750-780 nm
• Emission: 800-830 nm

Photothermal therapy:

• Dye concentration: 5-50 µM (in vitro) or 2-10 mg/kg (in vivo)
• Laser wavelength: 808 nm (common) or 785 nm
• Power density: 0.5-2 W/cm²
• Irradiation time: 5-10 minutes
• Controls: Laser only, dye only, laser + dye

Cyanine dyes are light-sensitive and require proper storage to maintain fluorescence properties.

Powder storage:

• Temperature: -20°C in freezer
• Light protection: Store in amber vial or wrap in aluminum foil
• Moisture: Keep dry, desiccated
• Atmosphere: Inert gas (argon/nitrogen) recommended
• Shelf life: 24 months when stored properly

Solution storage:

• Stock solutions (DMSO): -20°C in foil-wrapped tubes
• Aliquots: Single-use aliquots to avoid freeze-thaw
• Stability: 6-12 months at -20°C
• Working solutions: Prepare fresh, use within 24 hours

Handling precautions:

• Minimize exposure to light during weighing and preparation
• Work quickly under reduced lighting when possible
• Return to freezer immediately after use
• Use clean, dry spatulas for powder transfer

Signs of degradation:

• Color fading or change
• Reduced fluorescence intensity
• Shift in absorption/emission wavelengths
• Appearance of new peaks in HPLC

We offer multiple pack sizes for research applications.

Available quantities (in stock):

• 10 mg – Initial studies and method development
• 25 mg – Standard research quantity
• 50 mg – Extended imaging studies
• 100 mg – Large-scale in vivo studies
• Custom quantities: Available for production-scale needs

Usage estimates:

• 10 mg = sufficient for 100+ in vitro imaging experiments
• 25 mg = sufficient for 20-50 in vivo imaging studies
• Typical in vivo dose: 0.5-2 mg per mouse (2-5 mg/kg)
• Stock solution (10 mM in DMSO): 10 mg makes ~1.5 mL

Delivery times:

• Stock quantities: Ships within 24-48 hours
• Domestic USA: 2-3 business days (FedEx/UPS with ice packs)
• International: 5-7 business days (DHL/FedEx, refrigerated)
• Custom quantities: 2-3 weeks

Packaging:

• Amber vial with light protection
• Sealed under inert atmosphere
• Shipped refrigerated with ice packs
• Certificate of Analysis included
• Safety Data Sheet included