Fig. 4.

LDR-UA with padlock probes. a Padlock probes carry discriminating probe (DP) and common probe (CP) on a single molecule. The CP is normally shorter than DP to increase specificity. The padlock probe also contains two annealing sites for universal primers (indicated as an arrow and a dashed arrow), and a cZIP Code (jagged line). The padlock probe is circularized upon target recognition and ligation mediated by a ligase. b Circularized molecules are amplified with universal primers, one of which carries a fluorophore. c Amplification product is hybridized to a universal array