A new generation of Ca2+ indicators with greatly improved fluorescence properties.
A new family of highly fluorescent indicators has been synthesized for biochemical studies of the physiological role of cytosolic free Ca2+. The compounds combine an 8-coordinate tetracarboxylate chelating site with stilbene chromophores. Incorporation of the ethylenic linkage of the stilbene into a heterocyclic ring enhances the quantum efficiency and photochemical stability of the fluorophore. Compared to their widely used predecessor, "quin2", the new dyes offer up to 30-fold brighter fluorescence, major changes in wavelength not just intensity upon Ca2+ binding, slightly lower affinities for Ca2+, slightly longer wavelengths of excitation, and considerably improved selectivity for Ca2+ over other divalent cations. These properties, particularly the wavelength sensitivity to Ca2+, should make these dyes the preferred fluorescent indicators for many intracellular applications, especially in single cells, adherent cell layers, or bulk tissues.
D000634:Aminoquinolines; D001572:Benzofurans / Q000138:chemical synthesis; D002118:Calcium / Q000032:analysis*; D004910:Erythrocyte Membrane / Q000032:analysis; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000138:chemical synthesis*; D016257:Fura-2; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007211:Indoles / Q000138:chemical synthesis; D008274:Magnesium / Q000494:pharmacology; D008433:Mathematics; D013050:Spectrometry, Fluorescence; D013267:Stilbenes / Q000138:chemical synthesis
D000634:Aminoquinolines; D001572:Benzofurans; D005456:Fluorescent Dyes; D007211:Indoles; D013267:Stilbenes; D008274:Magnesium; C035739:Quin2; D002118:Calcium; D016257:Fura-2