Zincon monosodium salt

A colorimetric reagent for Zn, Cu and Hg detection and a metal indicator in EDTA titration. The aqueous solution of Zincon is yellow or orange-yellow in weak alkaline conditions, and turns blue in the presence of Cu (maximum wavelength, 600 nm, molar absorptivity, 1.9×104) and Zn (pH 8.5-9.5, maximum wavelength, 620 nm, molar absorptivity, 23,000). Used for the spectrophotometric determination of zinc, simultaneous determination of zinc and copper and for automated flow injection spectrometric determination of zinc. Binds nonspecifically proteins at acidic pH and was therefore used to stain proteins fast and background-free in sodium dodecyl sulfate polyacrylamide gel (SDS-Page). Sligthly less sensitivity than Coomassie Brilliant Blue®CBB but stains and destains more rapidly. Additionally, zincon staining is reversible, suggesting it might be applicable to 2-D PAGE and downstream analyses by mass spectrometry. Shown to inhibit insulin binding to its receptor and to attenuate the activity of ATPase and other enzymes, presumably because of the chelating properties of the dye.