Cyanines [Fluorescent Labels]

Cyanine dyes, including Cyanine3, Cyanine5, Cyanine5.5, Cyanine 7 and Indocyanine Green (= ICG) (Product No. I0535) are important compounds in biological applications. Among them, ICG, which is a heptamethine cyanine dye, has an absorption wavelength and an emission wavelength in the near-infrared window (about 800 nm), and is used for ophthalmic angiography and examining cardiac output, hepatic function, gaster/liver bloodstream. But ICG is nonspecific and cannot stain a certain tissue. Alternatively, researchers have been trying to utilize conjugates of heptamethine cyanine dye, which has functional group, with proteins including antibodies for diagnosis of a specific disease, drug release in a specific tissue, or fluorescence-guided surgery.^1-6) In particular, NIR fluorophore-mAb conjugates, which are complexes with monoclonal antibodies (mAbs), are useful as contrast agents for tumor targeting. As a near-infrared dye that can be conjugated with such antibodies, we introduce a cyanine dye that was added a carboxyl group into the polymethine structure of ICG.^7,8) ICG Carboxylic Acid (Product No. O0574) can be expected to be used as a material with characteristics that are close to but different from ICG, such as solubility and specific reactivity with biomolecules. For example, a probe for cellular hypoxia imaging that can "turn on" fluorescence with nitroreductase has been reported.⁹⁾
We offer ICG Carboxylic Acid at a lower price than ICG. We have 1 g and 5 g packages, and will be happy to discuss bulk synthesis requests.

In addition to ICG Carboxylic Acid, we also offer IR 754 Carboxylic Acid (Product No. C3693), IR 775 Chloride (Product No. I1026) and IR 783 (Product No. I1031). IR 783 can be used for conjugation with proteins such as antibodies because the functional group that can be conjugated with alcohol, amine, thiol and phenylboronic acid can be introduced into the chlorine moiety of the polymethine chain.^2,10)