Product Description: ZnAF-2, 6-iso- is a cell-impermeable compound that acts as a high-affinity Zn2 -specific fluorescent probe (Kd = 2.7 nM). It exhibits low basal fluorescence with an approximately 51-fold increase in fluorescence intensity upon stoichiometric (1:1) binding to Zn2 . Little affinity for Ca2 , Mg2 , Na or K .