Figure 2.

Schematic representation of molecular zipper in RAM reaction: A forward primer binds to a DNA circle and is continuously extended along the circle by a DNA polymerase, resulting in a long ssDNA with multiple repeats of circle sequence. Multiple molecular zippers, which serve as reverse primers, bind to the growing ssDNA and are extended by DNA polymerases, generating multiple ssDNAs by displacing downstream molecular zippers and their associated ssDNAs. To these ssDNAs, many forward primers bind and are extended by DNA polymerases. The negative strands of the molecular zippers are displaced by the polymerases when encountered. As a consequence, fluorescence emitted from the fluorophores of the negative strands can be detected.