Integrated RPA-CRISPR/Cas12a system towards Point-of-Care H. pylori detection

The rapidly advanced CRISPR/Cas biosensing technology provides unprecedent potential for the development of novel biosensing systems. It provides a new approach for realizing rapid, sensitivity and highly specific pathogen nucleic acid detection, with the capability to combine other technologies, including Polymerase Chain Reaction or isothermal amplifications. The detection of Helicobacter pylori (H. pylori), one of the most common human pathogens to cause various gastroduodenal diseases, has also been explored with the assistance of CRISPR/Cas systems. However, gaps still remain for the development of end-user friendly sensing systems. In this study, a combined RPA-CRISPR/Cas12a biosensing system has been established. It shown the capability to quantitively detect the presence of H. pylori genome DNA with 4 orders of magnitude linear range, and sensitivity of 1.4 copies/mu L. The overall reaction can be done within 45 mins at room temperature, which eliminates the needs for heating instrumentation. In addition, with the addition of pullulan as a protective reagent, the potential of storing CRISPR/Cas12a system reagents by using a freeze- dry approach has also been demonstrated.