The light-up probe is a peptide nucleic acid (PNA) oligomer to which an asymmetric cyanine dye thiazole orange (a single reporter dye) is tethered. Upon hybridization the thiazole orange moiety interacts with the nucleic acid bases and the probe becomes brightly (up to 50-fold) fluorescent (Svanvik, 2000a; 2000b & 2001;Isacsson, 2000; Wolffs, 2001). Being based on an uncharged analog (PNA), the light-up probe hybridizes faster and binds target DNA much stronger than oligonucleotide-based probes. See also LightUp Technologies.