6-Hydroxy-2-cyanobenzothiazole, Hydroxy-CBT



SKU: N/A Category:


Cyanobenzothiazole is a small molecule that can react very fast with 1,2-aminiothiol and also in a lesser extent with 1,2-diamine. Cyanobenzothiazole are not naturally present on biomolecules making it a good substrate for bioorthogonal reaction. 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 (Figure 1).1-3

Figure 1: Bioorthogonal reaction between CBT and 1,2-aminothiol


The Hydroxy group present on Hydroxy-CBT offers you the possibility to derivatize the CBT moiety with any molecule of interest.

Hydroxy-CBT can also be used for bioluminescence purposes since the reaction of Hydroxy-CBT with D-cysteine allows the formation of D-luciferin, a substrate for Firefly Luciferase.1

Material Amount Storage Stability
Hydroxy-CBT 50 mg

· 2-8 °C

· Desiccate

· Protect from light

When stored as directed, reactive probes are stable for at least 3 month
100 mg

Immediately before use dissolve D-Cys (10 mg) in 634 μL dilution buffer (final concentration 15.7 mg.mL-1). Dilute OH-CBT stock solution with 600 μL sterile PBS (final concentration 6.8 mg.mL-1). Once diluted those solution are quite unstable and should be injected in short time. Always prepare fresh solutions and discard at the end of the day.

In Vivo assay

Anesthetized mice were treated IP with D-Cys (100 uL), followed by OH-CBT (100 uL). Mice are then imaged using IVIS spectrum and bioluminescence signal is recorded every minute for 1h.

  1. White, E. H., McCapra, F., and Field, G. F. (1963) The structure and synthesis of firefly luciferin. J. Am. Chem. Soc., 85, 337-343.


  1. Nguyen, D. P., Elliott, T., Holt, M., Muir, T. W., and Chin, J. W. (2011) Genetically encoded 1,2-aminothiols facilitate rapid and site-specific protein labeling via a bio-orthogonal cyanobenzothiazole condensation. J. Am. Chem. Soc. 133, 11418-11421.


  1. Ren, H., Xiao, F., Zhan, K., Kim, Y., Xie, H., Xia, Z., and Rao, J. (2009) A biocompatible condensation reaction for the labeling of terminal cysteine residues on proteins. Angew. Chem., Int. Ed. 48, 9658-9662.

Light yellow powder

Product Size

1 kit

Molecular Weight

176.19 g.mol-1



Cas Number



up to 50% DMSO, 25% DMF, EtOH, MeOH, 1,3 propyleneglycol, 50% Polyethyleneglycol400 PEG400, PEG400+Chremophore+PBS (1:1:12)

Shipping condition


Regulator Statement

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


50 mg, 100 mg


There are no reviews yet.

Be the first to review “hydroxy-CBT”