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for microscopy

IC Green, Indocyanine green, Foxgreen
Empirical Formula (Hill Notation):
CAS Number:
Molecular Weight:
EC Number:
MDL number:
PubChem Substance ID:

Quality Level


for microscopy




water: 0.01 g/10 mL

ε (extinction coefficient)

≥115 at 386-396 nm in water
≥2000 at 774-784 nm in water
≥900 at 712-722 nm in water


diagnostic assay manufacturing

storage temp.

room temp

SMILES string




InChI key


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General description

Cardiogreen is a dye used for microscopy. This dye has its maximum extinction at the same wavelength as reduced and oxygenated haemoglobin meet making it possible to record the oxygen saturation in blood. This dye has no side-effects.


Cardiogreen was injected in animals intravenously for dynamic optical imaging system to study the capability of capturing the in vivo biodistribution kinetics.


Bottomless glass bottle. Contents are inside inserted fused cone.

Other Notes

A diagnostic aid in the determination of hepatic function


Exclamation mark

Signal Word


Hazard Statements

Precautionary Statements

Hazard Classifications

Eye Irrit. 2 - Skin Irrit. 2 - STOT SE 3

Target Organs

Respiratory system

Storage Class Code

11 - Combustible Solids



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Certificate of Analysis

Certificate of Origin

More documents

Quotes and Ordering

  1. How does the storage temperature relate to shipping conditions?

    The storage conditions that a Sigma-Aldrich catalog and label recommend for products are deliberately conservative. For many products, long-term storage at low temperatures will increase the time during which they are expected to remain in specification and therefore are labeled accordingly. Where short-term storage, shipping time frame, or exposure to conditions other than those recommended for long-term storage will not affect product quality, Sigma-Aldrich will ship at ambient temperature. The products sensitive to short-term exposure to conditions other than their recommended long-term storage are shipped on wet or dry ice. Ambient temperature shipping helps to control shipping costs for our customers. At any time, our customers can request wet- or dry-ice shipment, but the special handling is at customer expense if our product history indicates that the product is stable for regular shipment. See Shipping and Storage for more information.

  2. Which document(s) contains shelf-life or expiration date information for a given product?

    If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.

  3. How do I get lot-specific information or a Certificate of Analysis?

    The lot specific COA document can be found by entering the lot number above under the "Documents" section.

  4. How do I find price and availability?

    There are several ways to find pricing and availability for our products. Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote.  USA customers:  1-800-325-3010 or view local office numbers.

  5. What is the Department of Transportation shipping information for this product?

    Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product. 

  6. Has Cardiogreen been used for in vivo optical imaging studies?

    We do not subject this product to in vivo testing. However, one study documents the use of the product in a study with mice:For optical imaging, mice were injected intravenously with a mixture of 0.05 ml of 260 μM ICG (Cardiogreen) and 0.05 ml of 360 μM DTR (70,000 MW, Invitrogen) in saline (equivalent to 0.4 mg per kg or 7.4 μM initial concentration in blood).

  7. Does Cardiogreen dissolve equally well in saline and in water?

    Each lot is tested for solubility in hot water at 1 mg/mL. We have found that Sigma Product No. I2633 (which has the same CAS number as Product No. 21980) dissolves in water at 1 mg/mL without heating. Further dilute in saline to prepare an isotonic solution.

  8. How long can I store a solution of Cardiogreen after it has been prepared?

    Sigma-Aldrich recommends that solutions be prepared fresh and not stored. Solutions "are stable only for a few hours and cannot be kept overnight." See: Sigma-Aldrich Handbook of Dyes, Stains, and Indicators, Green, F. ed., p. 407.

  9. Can Product No. I2633, Cardiogreen, be used as a biological stain?

    Limited absorbance in the visible region practically precludes the use of Indocyanine Green as a biological stain. See: Sigma-Aldrich Handbook of Dyes, Stains, and Indicators, Green, F. ed., p. 407.

  10. My question is not addressed here, how can I contact Technical Service for assistance?

    Ask a Scientist here.

Elizabeth M C Hillman et al.
Nature photonics, 1(9), 526-530 (2008-11-01)
Optical molecular imaging in small animals harnesses the power of highly specific and biocompatible contrast agents for drug development and disease research1-7. However, the widespread adoption of in vivo optical imaging has been inhibited by its inability to clearly resolve
Determination of cardiac output with cardio green in a direct writing colorimeter.
B HYSING et al.
Scandinavian journal of clinical and laboratory investigation, 14, 430-434 (1962-01-01)
C.M. Leevy et al.
Probl. Liver Dis. (Review), 42-42 (1979)
H M Mathéron et al.
Gynecologic oncology, 131(3), 720-725 (2013-09-21)
Conventional sentinel node (SN) mapping is performed by injecting a radiocolloid followed by lymphoscintigraphy (and SPECT/CT imaging). An extra intraoperative injection with blue dye can then allow for optical identification of the SN. In order to improve the current clinical
Michele Diana et al.
Annals of surgery, 259(4), 700-707 (2013-03-28)
Our aim was to evaluate a fluorescence-based enhanced-reality system to assess intestinal viability in a laparoscopic mesenteric ischemia model. A small bowel loop was exposed, and 3 to 4 mesenteric vessels were clipped in 6 pigs. Indocyanine green (ICG) was

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