IR820 Cyanobenzothiazole, IR820-CBT probe-Background


 140.00 895.00

Labeling via cysteine click chemistry

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IR820 is a non-invasive near-infrared (NIR) fluorescence imaging dye that belongs to the family of the heptamethine dyes and has a rigid cyclohexenyl ring, increasing molecular stability and photostability. IR820 could be used as both an imaging dye and a hyperthermia agent.1

IR820 has a little absorption in the visible range thus exhibit low autofluorescence, tissue absorbance, and scatter at NIR wavelengths (700-900 nm).


Cyanobenzothiazole (CBT) derivatives of the IR820 dye offer the opportunity to develop optimal conjugates. Cyanobenzothiazole reactive groups provide an efficient and convenient way to selectively link IR820 dyes to 1,2-aminothiol, such as Cysteine residue on various substrates (Antibodies, peptides, proteins, nucleic-acid, small molecule drug…). Cyanobenzothiazole are very reactive against 1,2-aminiothiol and also showed in a lesser extent reactivity against 1,2-diamine. Cyanobenzothiazole are non-endogeneous functional groups, thus they are not naturally present on targeting molecules (biomolecules). On the other hand, 1,2-aminothiol is present in nature, being the motif of the rare aminoacid cysteine (Cys). It is noteworthy that endogenous Cys in peptides and proteins would react with CBT derivatives only when it is present at the N-terminal position (since the amino group is needed free for the reaction). The reaction proceeds under aqueous conditions at physiological temperatures and pressures. The CBT/1,2-aminothiol combination is thus a bioorthogonal reaction.

Material Amount Storage Stability
IR820-CBT 1 mg
  • -20° C
  • Desiccate
  • Protect from light
When stored as directed, reactive probes are stable for at least 3 months
5 mg
10 mg

Immediately before use, dissolve the IR820-CBT dyes in anhydrous dimethylsulfoxide (DMSO). Once reconstituted, this reactive probe solution is somewhat unstable, especially in presence of moisture that can slowly hydrolyze the cyano- group to the non-reactive species.

The IR820-NHS dye can virtually be conjugated to any primary amine-containing molecule such as peptides, proteins, antibodies, small-molecule drugs… If possible avoid nucleophilic bases, since it will partially degrades IR820 core structure to non-NIR-fluorescent by-products.

Typical antibody conjugation reactions are carried out in 0.1–0.2 M sodium bicarbonate buffer, pH 8.3, at room temperature for 1 hour. We recommend trying different molar ratio between antibodies and reactive dyes in order to reach your needs.


Conjugate Purification

Labeled antibodies are typically separated from free IR820 dye using a gel filtration column, such as SephadexTM G-25, BioGel® P-30, or equivalent. For much larger or smaller proteins, select a gel filtration media with an appropriate molecular weight cut-off or purify by dialysis.

  1. Fernandez-Fernandez A., Manchanda R., Lei T., Carvajal D.A., Tang Y., Kazmi S.Z.R., and McGoron A.J., Comparative Study of the Optical and Heat Generation Properties of IR820 and Indocyanine Green, Molecular Imaging, 2012, 11, 99–113

Dark brown powder



Product Size

1 kit

Detection Method

Fluorescence, optoacoustic

Excitation Class

Near infrared, NIR

Excitation/Emission maximum (nm)


Molecular Weight

967.23 g.mol-1



Shipping Condition


Regulatory Statement

For Research Use Only. Not for use in diagnostic procedures.


1 mg, 5 mg, 10 mg


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