Development of “NEC-SD-LAMP,” a New Non-Electrified Infectious Diseases Testing Method
Abstract Here, non-electric-control SalivaDirect loop-mediated isothermal amplification (NEC-SD-LAMP), which can detect infections by analyzing viral gene expression in saliva without electrical control systems, was developed. In this method, viral genes are purified from saliva using SalivaDirect, and gene expression is analyzed by loop-mediated isothermal amplification (LAMP) by adding water to the device, and the results can be visually confirmed. Melting palmitic acid maintains the optimal temperature for the LAMP reaction, as the temperature of palmitic acid is maintained at 62.9°C, its melting point. By taking advantage of the proximity of this melting point to the optimal temperature for LAMP, it is possible to perform LAMP without electricity. Using this method, adenovirus DNA was detected in saliva. Furthermore, the detection limit was 2 copies per µL, indicating that it is possible to detect viral infections in saliva even before the onset of SARS-CoV-2 infection.