Figure 5: b) scheme of the PNA-PNA
ligation-replication cycle, starting with
one duplex (top) and ending with two (bottom). The strategy is to
measure the replicating turnover via FRET signal (bulb symbol)
appearing only
upon the formation of duplexes; hence the enhancement of the signal
after
each replication round. Building-block oligomers are asymmetric,
kvatromers and hexamers, to ensure lower hybridization tendency of
kvatromers and
hence lower signal that is not due to ligation. Kvatromers as well as
templates have FRET dyes so that duplexes have dyes at the opposite
ends since this combination generated the highest FRET signal.