ICG

Indocyanine Green (ICG) is a clinically approved near-infrared (NIR) fluorescent dye widely used in medical diagnostics, in vitro and in vivo studies, and animal model research. This versatile dye offers exceptional imaging capabilities, allowing for deep tissue visualization from the skin surface, which has led to its extensive application across various research fields and clinical practices.

ICG exhibits remarkable optical characteristics such as excitation/emission maxima of 785/812 nm, 
extinction coefficient of 240,000 cm?¹M?¹ and CF280 of 0.05. The dye can be effectively excited using 750-800 nm laser lines or LED sources. When injected into the human body, ICG rapidly binds to plasma proteins, primarily high-density lipoproteins, resulting in a red-shifted fluorescence emission peak at approximately 845 nm14. This shift enhances its utility for in vivo imaging applications.

*It's important to note that ICG in aqueous solutions is unstable over time. For optimal results, freshly prepared solutions should be used in experimental and clinical applications*

ICG's unique properties make it invaluable in various medical fields: 
-Angiography: Particularly useful in ophthalmology for visualizing choroidal blood flow and detecting neovascularization in age-related macular degeneration.
-Lymphatic Mapping: Essential in cancer surgeries, especially for breast cancer and melanoma, aiding in sentinel lymph node identification.
-Intraoperative Imaging: Used in various surgical procedures for real-time visualization of vascular flow, tissue perfusion, and critical anatomical structures.
-Perfusion Assessment: Helps in evaluating organ perfusion, particularly useful in transplant surgeries and assessing anastomosis integrity.
-Tumor Imaging: Aids in tumor detection and margin assessment in various cancers. 

ICG's unique combination of optical properties, safety profile, and versatility has established it as a cornerstone in fluorescence-guided imaging and surgery. As research continues, its applications are likely to expand further, potentially revolutionizing various aspects of medical diagnostics and surgical interventions.

What are the advantages?
1. Deep Tissue Imaging: NIR fluorescence allows for deeper tissue penetration compared to visible light, enabling imaging of structures several millimeters below the skin surface. 
2. Safety Profile: ICG is FDA-approved and has a low toxicity profile, making it suitable for human use. 
3. Versatility: Its applications span across multiple medical specialties, including ophthalmology, oncology, and vascular surgery. 
4. Real-time Imaging: Provides immediate, real-time visualization during procedures, enhancing surgical precision and decision-making. 
5. Stability Concerns: The instability of ICG in aqueous solutions necessitates careful preparation and timely use.   
 

Specifications

• Fluorophore: ICG
• Reactive group: None
• Excitation/Emission Max.(nm): 785/812
• Extinction coefficient: 240,000 cm-1M-1
• CF280: 0.05
• Appearance: Green Solid
• Molecular Weight: 752.98 g/mol
• Solubility: DMF, DMSO
• Storage conditions: 4 ℃, protect from light

Quick link (Cat.#)	Series	Quick link (Cat.#)	Series
RFP0815	ICG	RFP0915	ICG (water-soluble)
POS1604	ICG NHS ester	POA1616	ICG Vinylsulfone
POSN1604	ICG Sulfo-NHS ester	POI1616	ICG Isothiocyanate
POC1616	ICG Carboxylic acid	PWM1301	ICG Maleimid
POE1616	ICG Amine	PWT1301	ICG Thiol
POR2616	ICG Dichlorotriazine	POH1616	ICG Hydrazide
POK1616	ICG Alkyne	POG1616	ICG PEG4-Alkyne
DOC1061	ICG ADIBO	POZ1616	ICG Azide

Background

ICG Dyes

ICG is clinically approved NIR dye and used in medical diagnostics, in vitro, vivo and animal model study. NIR fluorescence allows to observe the deep image from the surface of skin and its usage spreads to a wide range of research fields. ICG fluorescence method is safe and cost effective technique and used in a wide range of medical fields such as breast cancer sentinel lymph node navigation, detecting cerebral vessels, coronary arteries and biliary trees, tracking tumor location, detecting small HCC, etc. The method has several advantages such as radiation free, compact instrumentation, real-time monitoring, easy operation, etc. The maximum excitation/emission values of ICG are 785/821 nm. When ICG is injected into a human body, it rapidly bound to plasma protein, mainly high-density lipoprotein, and generates red-shifted fluorescence (845 nm). ICG in aqueous solution is unstable over time, thus the fresh solution should be used for effective trials. BioActs provides ICG dye for biological research and medical diagnostics and also offers various reactive and functionalized ICG dyes for labeling of antibodies, peptides, proteins and ligands.

Table 1.  ICG dye applications

 

Figure 1.  Structure of Indocyanine Green (ICG) dye

Citation & Reference

1. Masashi Gotoh. Development of a canine model of pulmonary emphysema and imaging of the emphysematous lung with infrared thoracoscopy. J Thorac Cardiovasc Surg 126.6 (2003): 1916-21.

2. Aaron M. Mohs. An integrated widefield imaging and spectroscopy system for contrast-enhanced, image-guided resection of tumors. IEEE Trans Biomed Eng 62.5 (2015): 1416-24.

3. Mohammed Hassan. Near Infrared Fluorescence Imaging with ICG in TECAB Surgery Using the da Vinci Si Surgical System in a Canine Model. J Card Surg 27.2 (2012): 158-162.

4. R. C. Benson. Fluorescence properties of indocyanine green as related to angiography. Phys Med Biol 23.1 (1978): 159-63.

5. Mitsuharu Miwa. The Principle of ICG Fluorescence Method. The Open Surgical Oncology Journal 2 (2010): 26-28.