Europium cryptate labeled deoxyuridine-triphosphate analog: Synthesis and enzymatic incorporation

The synthesis of an europium tris-bipyridine cryptate labeled 2'-deoxyuridi ne-5'-triphosphate analog (K-11-dUTP) is described. This labeled triphospha te was incorporated into DNA through enzymatic reactions with terminal tran sferase and DNA polymerases. The enzymatic reactions were monitored by TRAC E (Time Resolved Amplification of Cryptate Emission), a homogeneous method using Fluorescence Resonance Energy Transfer (FRET) from an europium crypta te as donor to a modified allophycocyanine as acceptor.