Cu(2+)-labeled dansyl compounds as fluorescent and PET probes for imaging apoptosis.

Compound DNSTT-Cu(2+), a novel chelate of Cu(2+) with DOTA conjugated to a fluorescent dansyl fragment, is developed for imaging cell apoptosis. Apoptotic U-87MG cells could be selectively visualized by the fluorescence of DNSTT-Cu(2+) from cytoplasm of cells, confirmed by the fluorescence of apoptosis cells co-labeled with Alexa Fluor 568-labeled annexin V, a conventional probe for selectively labeling membranes of apoptosis cells. A radioactive (64)Cu(2)(+) analog, DNSTT-(64)Cu(2+), was easily synthesized, providing a potential PET probe for imaging apoptosis in vivo.