摘要 |
A process is provided to generate fluorescent molecules in the presence of target nucleic acids, but not in the absence of that target. Two probes, one bearing moiety A and the other bearing moiety B, bind to the target in a way that brings A and B together. A photon then converts A into A*, which can react with B to form a new species Z that is fluorescent. If A* does not encounter B, then A* reverts to form A. This allows the probe to have another opportunity to be activated should it be later bound near B. In one embodiment, a photoenolization creates A* as a diene; this reacts with a dienophile B in a Diels-Alder reaction. The linker Z may cause the linked probes to bind less tightly to the target, allowing the target to generate many fluorescent products, or be read through by a polymerase.
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