6-Methoxy-(8-''p''-toluenesulfonamido)quinoline (TSQ) is one of the most efficient fluorescent stains for

zinc Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic tabl ...

(II). It was introduced by Soviet

biochemist Biochemists are scientists who are trained in biochemistry. They study chemical processes and chemical transformations in living organisms. Biochemists study DNA, proteins and Cell (biology), cell parts. The word "biochemist" is a portmanteau of ...

s Toroptsev and Eshchenko in the early 1970s. The popularity of TSQ as physiological stain rose after seminal works by Christopher Frederickson two decades later.See for example: TSQ forms a 2:1 (ligand-metal) complex with zinc and emits blue light upon

excitation Excitation, excite, exciting, or excitement may refer to: * Excitation (magnetic), provided with an electrical generator or alternator * ''Exite'', a series of racing video games published by Nintendo starting with ''Excitebike'' * Excite (web port ...

at 365 nanometers. TSQ has been extensively applied for determination of extracellular or intracellular levels of Zn²⁺ in biological systems, also to study Zn²⁺ in mossy fibers of the

hippocampus The hippocampus (: hippocampi; via Latin from Ancient Greek, Greek , 'seahorse'), also hippocampus proper, is a major component of the brain of humans and many other vertebrates. In the human brain the hippocampus, the dentate gyrus, and the ...

References

Fluorescent dyes Quinolinols Sulfonamides Aromatic amines {{Biochem-stub