| abstract |
A fluorescent compound, which is readily capable of forming a stable complex with a rare-earth metal ion having fluorescence with satisfactory intensity even in an aqueous system and long fluorescence lifetime when formed a complex with the rare-earth metal ion, a complex of the fluorescent compound and the rare-earth metal ion, and a labelled reagent made therefrom, together with a specific binding assay using said labelling agent. n A fluorescent compound expressed by the following formula A, typically exemplified by 2,15-diaza[3,3](2,9)-1,10-phenanthrolinophane-N²,N¹⁵-diacetic acid. n Formula A |