BHQ-3 carboxylic acid chloride 

BHQ‑3 carboxylic acid is an azo‑containing dark fluorescence quencher. BHQ‑3 carboxylic acid is conjugated to an MMP‑cleavable peptide and paired with a fluorophore to form an activatable probe for MMP activity detection in vitro. BHQ‑3 carboxylic acid shows maximal absorption in the 620 to 730 nm range. BHQ‑3 carboxylic acid–based fluorescent probes can be used in the research of arthritis and tumor‑related pathological processes.^[1].

BHQ-3 carboxylic acid efficiently quenches IRDye 800CW fluorescence via contact quenching instead of FRET, due to insufficient spectral overlap^[1].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

BHQ-3 carboxylic acid (40 nmol; i.v.; single dose) confers in vivo instability to IRDye 800CW-conjugated constructs in normal mice, as evidenced by rapid azo bond cleavage of the quencher moiety^[1].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

583.12

C₃₃H₃₅ClN₆O₂

Solid

Dark purple to black

O=C(CCCN(C)C1=CC=C(C=C1)/N=N/C2=CC3=C(N=C4C=CC(N(CC)CC)=CC4=[N+]3C5=CC=CC=C5)C=C2)O.[Cl-]

Room temperature in continental US; may vary elsewhere.

-20°C, sealed storage, away from moisture and light

*In solvent : -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture and light)

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture and light). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

• [1]. Linder KE, et al. Synthesis, in vitro evaluation, and in vivo metabolism of fluor/quencher compounds containing IRDye 800CW and Black Hole Quencher-3 (BHQ-3). Bioconjug Chem. 2011 Jul 20;22(7):1287-97.

  [2]. Chevalier A, et al. Bioconjugatable azo-based dark-quencher dyes: synthesis and application to protease-activatable far-red fluorescent probes. Chemistry. 2013 Jan 28;19(5):1686-99.  [Content Brief]