Fig. 2.

Working principle of linear FRET probes for nuclei acid detection. Two oligos are designed to base pair with the target RNA at adjacent sequences. One oligo is labeled with a donor chromophore at the 3′ end (Donor Probe). The other oligo is labeled with an acceptor chromophore at the 5′ end of the sequence (Acceptor Probe). Once the two oligos anneal to the target RNA, the chromophores are brought into proximity. Now, under light illumination, the donor probe will transfer energy to the acceptor probe and emit in NIR spectrum