All-in-one microfluidic device for on-site diagnosis of pathogens based on an integrated continuous flow PCR and electrophoresis biochip

Current continuous flow polymerase chain reaction (CF-PCR) microfluidic chips require external precision syringe pumps and off-line methods (e.g., electrophoresis and hybridization) to detect PCR products, resulting in complex operations and possible cross-contamination and consequently CF-PCR is still confined to laboratories. Herein, a portable all-in-one microfluidic device is fabricated for rapid diagnosis of pathogens based on an integrated CF-PCR and electrophoresis biochip. A new method was proposed for automatic sample injection into the chip which can substitute the costly external precision syringe pump. It not only achieves rapid DNA amplification and on-site PCR product detection, but also realizes automatic sample injection. As an application, three periodontal pathogens (e. g., Porphyromonas gingivalis, Treponema denticola and Tannerela forsythia) were successfully amplified in the device. Treponema denticola was amplified in as short as 2' 31, and detection of PCR products was completed within 3' 43. The minimum number of bacteria that can be amplified was 125 cfu per mu l. The all-in-one device has the potential to be applied in point-of-care nucleic acid testing for diseases.