Figure 1. Fluorescent probes to detect the NER dual incisions.

(a) A linear duplex containing the (6–4) photoproduct and the fluorophore–quencher pair. Detection of the dual incisions in cells was not successful due to nonspecific degradation. (b) A plasmid-type probe containing the fluorophore and the quencher in the same strand. Degradation of the dual-incision product by cellular nucleases was expected to obtain the positive signal.