A Portable, Rapid Isothermal Nucleic Acid Amplification System with Integrated Microfluidics for Pandemic Surveillance

Integration of small-footprint cost-effective isothermal rapid DNA extraction, amplification, and detection systems is crucial to achieving a point-of-care pathogen detection system suitable for resource-limited locations. The herein system measures low-level fluorescent signals in real-time during nucleic acid amplification, while maintaining the desired assay temperature on a low-power, portable footprint. A thermally stable microfluidic device was implemented to mitigate thermocapillary effects and facilitate optical alignment for automated image capture and signal analysis. The system uses Loop-Mediated Isothermal Amplification with primers sensitive to broad strains and lineages of SARS-CoV-2 with viral loads corresponding to cycle thresholds from 16 to 39. Among the 54 samples tested through optimizations, the platform yielded an 84% true positive rate. Preliminary investigations were conducted on developing an electromagnetic extraction process by printing a conductive coil around a microfluidic channel. The extraction module was designed to be integrated with the detection system into a sample-to-results point-of-care system.