Azure A chloride 

Azure A chloride is a phenothiazine dye. Azure A chloride is an alternative DNA dye used for the separation of DNA and protein fragments in agarose gel electrophoresis and PAGE. Azure A chloride can be chemisorbed on the surface of mild steel according to the Langmuir adsorption isotherm to form a protective film. Azure A chloride binds to double-stranded DNA in a non-cooperative manner via weak intercalation, triggering molecular conformational disturbance, restricted rotational motion, and changes in optical activity^[1][2][3].

Azure A chloride (1-100 μM; 1-120 h, 298-328 K) acts as a stable, mixed-type corrosion inhibitor for mild steel in 1.0 M HCl, achieving a maximum inhibition efficiency of 88% at 100 μM after 1 h immersion at 298 K, and maintaining efficiencies above 86% even after 120 h of exposure at the highest concentration^[2].
Azure A chloride inhibits mild steel corrosion via electron donation from nitrogen atoms (N19, N30) and heterocyclic ring carbon atoms (C3, C8) to the metal surface, with enhanced electron-donor activity in aqueous acidic conditions, supporting a chemisorption mechanism^[2].
Azure A chloride (1-60 μM; incubated at 20 ± 0.5-1.0°C) binds to herring testes double-stranded DNA in a non-cooperative, weak intercalative manner with an intrinsic binding constant of ~0.88 × 10⁵/M, a binding stoichiometry of ~4.5 base pairs per dye molecule, and induces minor changes to DNA conformation and optical activity in the dye molecule^[3].

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

291.81

C₁₄H₁₄ClN₃S

531-53-3

Solid

Brown to black

CN(C1=CC2=[S+]C3=C(C=CC(N)=C3)N=C2C=C1)C.[Cl-]

Room temperature in continental US; may vary elsewhere.

4°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)

• [1]. M. Snehalatha, et al. Azure A chloride: computational and spectroscopic study. J. Raman Spectrosc. 2009, 40, 176-182.

  [2]. Demet Özkır, et al. The inhibition effect of Azure A on mild steel in 1 M HCl. A complete study: Adsorption, temperature, duration and quantum chemical aspects. Corrosion Science 56 (2012) 143-152.

  [3]. Paul P, et al. Spectroscopic studies on the binding interaction of phenothiazinium dyes toluidine blue O, azure A and azure B to DNA. Spectrochim Acta A Mol Biomol Spectrosc. 2013;107:303-310.  [Content Brief]