Picoliter Well Array Chip-Based Digital Recombinase Polymerase Amplification for Absolute Quantification of Nucleic Acids

Li, Zhao; Liu, Yong; Wei, Qingquan; Liu, Yuanjie; Liu, Wenwen; Zhang, Xuelian; Yu, Yude

To avoid thermal cycling, different isothermal amplification methods have been developed that rapidly amplify nucleic acids to detectable levels at a single temperature [42, 43] , such as loop-mediated amplification (LAMP) [44] , rolling circle amplification (RCA) [45] , helicasedependent amplification (HDA) [46] , nucleic acid sequence-based amplification (NASBA) [47] , recombinase polymerase amplification (RPA) [48] , transcription-mediated amplification (TMA) [49] , multiple displacement amplification (MDA) [50] , and strand-displacement amplification (SDA) [51] . In contrast to other isothermal amplification techniques, RPA offers several important advantages for point-of-care applications: it requires a lower amplification temperature of between 25°C and 42°C, is tolerant to impure samples, amplifies targets to detectable levels more rapidly (15-30 min) , and uses lyophilized enzymes without cold chain storage and transport [48] .