Table 19.6 Fluorescent indicators for Zn2+.

Indicator Water-Soluble Salt Cell-Permeant Ester Ex/Em * Kd for Zn2+ †
FluoZin-1 F24180 F24181 495/515 8 µM
FluoZin-2 NA F24189 495/525 2 µM
FluoZin-3 F24194 F24195 494/516 15 nM **
RhodZin-3 R36350 R36351 550/575 65 nM
Newport Green DCF N7990 N7991 505/535 1 µM
Newport Green PDX NA N24191 495/520 30 µM
* Excitation (Ex) and Emission (Em) maxima, in nm. † Dissociation constant of the indicator Zn2+ complex measured in 50 mM MOPS, pH 7.0, at 22°C. ‡ Excitation peak shifts upon binding Zn2+. § Emission peak shifts upon binding Zn2+. ** Kd determined in 135 mM NaCl, 1.1 mM EGTA, 20 mM HEPES, pH 7.4, 0–10 µM free Zn2+ at 22°C. NA = Not available.