title: A handheld flow genetic analysis system (FGAS): towards rapid, sensitive, quantitative and multiplex molecular diagnosis at the point-of-care level.
abstract: A handheld flow genetic analysis system (FGAS) is proposed for rapid, sensitive, multiplex and real-time quantification of nucleic acids at the point-of-care (POC) level. The FGAS includes a helical thermal-gradient microreactor and a microflow actuator, as well as control circuitry for temperature, fluid and power management, and smartphone fluorescence imaging. All of these features are integrated into a field-portable and easy-to-use molecular diagnostic platform powered by lithium batteries. Due to the unique design of the microreactor, not only steady temperatures for denaturation and annealing/extension but also a linear thermal gradient for spatial high-resolution melting can be achieved through simply maintaining a single heater at constant temperature. The smartphone fluorescence imaging system has a wide field of view that captures all PCR channels of the microreactor in a single snapshot without the need for any mechanical scanning. By these designs, the FGAS enables real-time monitoring of the temporal and spatial fluorescence signatures of amplicons during continuous-flow amplification. On the current FGAS, visual detection of as little as 10 copies per μL of genomic DNA of Salmonella enterica was achieved in 15 min, with real-time quantitative detection of the DNA over 6 orders of magnitude concentration from 10(6) to 10(1) copies per μL also completed in 7.5-15 min. In addition, multiple pathogenic DNA targets could be simultaneously discriminated with direct bar-chart readout or multiplex spatial melting in serial flow. We anticipate that the FGAS has great potential to become a next-generation gene analyzer for POC molecular diagnostics.
authors.affiliation: MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China. zhangcs@scnu.edu.cn zhangcs_scnu@126.com xingda@scnu.edu.cn.
authors.forename: Bowen
authors.initials: B
authors.lastname: Shu
authors.forename: Chunsun
authors.initials: C
authors.lastname: Zhang
authors.forename: Da
authors.initials: D
authors.lastname: Xing
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics; D001424:Bacterial Infections / Q000175:diagnosis / Q000382:microbiology; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D006801:Humans; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D025202:Molecular Diagnostic Techniques / Q000295:instrumentation*; D061848:Optical Imaging / Q000295:instrumentation*; D019095:Point-of-Care Systems; D016133:Polymerase Chain Reaction / Q000295:instrumentation; D000068997:Smartphone
chemical_list: D004269:DNA, Bacterial