of the one-photon absorption and emission spectra in nm. [b]Fluorescence quantum yield. [c]Dissociation constants measured by one- () and two-photon () processes, except otherwise noted. [d]Fluorescence enhancement factor, , measured by one-photon processes. The number in parentheses is measured by two-photon process. [e] and represent the maximum and minimum ratios of , where and are the fluorescence intensities measured at 425–475 nm () and 525–575 nm (), respectively. The number in parentheses was measured by two-photon process. of the two-photon excitation spectra in nm. [g]The peak two-photon action cross-section in 10−50 cm4 s/photon (GM). [h]Measured in MOPS buffer (30 mM MOPS, 100 mM KCl, 10 mM EGTA, pH 7.2) in the absence and presence (120 nM) of free Zn2+. [i]Measured in HEPES buffer (50 mM HEPES, 100 mM KCl, 10 mM NTA, pH 7.4) in the absence and presence (47 nM) of free Zn2+. [j]Measured in MOPS buffer (30 mM MOPS, 100 mM KCl, pH 7.4) before and 2 h after addition of 10 mM GSH. [k]Measured in MOPS buffer (30 mM MOPS, 100 mM KCl, pH 7.4) before and 1 h after addition of 1 mM H2O2.