Chemical Description: 2-Benzothiazolyl-3-(4-carboxy-2-methoxyphenyl)-5-[4-(2-sulfoethylcarbamoyl)phenyl]-2H-tetrazolium
Appearance: Yellow or brown powder
Molar absorptivity (pH8): ≥28,000 (around 265 nm)
MW: 580.59, C25H20N6O7S2
Storage Condition : 0-5ºC, protect from light
Shipping Condition: ambient temperature
Product Description of WSTs
Water-soluble tetrazolium salts (WSTs) were developed by introducing positive or negative charges and hydroxy groups to the phenyl ring of the tetrazolium salt. Positive charges, such as trialkylammonio groups, improve the water-solubility of the formazan dye. However, a large cation is easily precipitated out with organic anions such as carboxylate or phosphate. Though a hydroxy group also improved the water-solubility of the tetrazolium salt, the corresponding formazan dye was not sufficiently water-soluble. Dojindo’s WSTs have sulfonate groups added directly or indirectly to the phenyl ring to improve water-solubility. Dojindo also offers several newly developed phenlyazo-type tetrazolium salts, which are easily reduced with NADH or other reducing agents to give orange or purple formazan dyes. Due to the phenylazo group, the color changes with heavy metal ion. Since the water solubility of Dojindo’s WSTs is high (except WST-10), 10 mM to 100 mM solutions can be prepared.
WST-4, 5: M. Ishiyama, et al., Anal. Sci., 12, 515 (1996).
Fig 2 Absorption Spectra of WST Formazan Dyes