Integrated slip valve-assisted fluidic chip coupling with CRISPR/Cas12a system for nucleic acid analysis

Currently, some on-site nucleic acid detection platforms have been developed. However, these platforms still need to be improved in device integration and multiple detection capability. In this work, an integrated dual nucleic acid analysis platform was developed by slip valve-assisted fluidic chip coupled with CRISPR/Cas12a system. All the reagents, including nucleic acid extraction, air-dried loop-mediated isothermal amplification (LAMP) and CRISPR/Cas12a detection reagents, were preloaded on the fluidic chip. Liquids transfer and stirring could be controlled by a slip valve and a syringe. By combining duplex LAMP reaction with two CRISPR detection units, CRISPR/Cas12a-based dual nucleic acid analysis was successfully constructed. Benefiting from high-quality nucleic acid extraction on the chip, as low as 30 copies/reaction of Vibrio parahaemolyticus (V. parahaemolyticus) and 20 copies/reaction of Salmonella typhimurium (S. typhimurium) could be simultaneously detected. Detection results could be observed by the naked eye under a portable ultraviolet lamp. The whole detection procedure was finished within 60 min. This method with integrated nucleic acid analysis, dual detection capability and fluorescence visualized results provides a new solution for on-site nucleic acid analysis.