Exponential quadruplex priming amplification for DNA-based isothermal diagnostics

Polymerase chain reaction (PCR) is a method of choice for molecular diagnostics. However, PCR relies on thermal cycling, which is not compatible with the goals of point-of-care diagnostics. A simple strategy to turn PCR into an isothermal method would be to use specific primers, which upon polymerase elongation can self-dissociate from the primer-binding sites. We recently demonstrated that a monomolecular DNA quadruplex, GGGTGGGTGGGTGGG, meets these requirements, which led to the development of the linear versions of quadruplex priming amplification (QPA). Here we demonstrate exponential version of isothermal QPA, which allows an unprecedented 10(10)-fold amplification of DNA signal in less than 40 min.