Smallest dual-color qPCR device

The global outbreak of the coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), necessitated the development of point-of-care (POC) systems for rapid and widespread population screening. Current POC systems, based on reverse transcription–quantitative polymerase chain reaction (RT-qPCR) methods, are unable to perform RNA target multiplexing, which is crucial for specific viral strain identification. This study presents a compact qPCR system capable of dual fluorescence channel gene multiplexing by simultaneously detecting two targets of the SARS-CoV-2 virus using 6-carboxyfluorescein (FAM)- and TxRed-labeled probes. The device measures (110 × 83 × 41) mm3 and weighs 210 gm. It features four virtual reaction chambers, a thermal cycle system, a real-time optical signal detection module, a USB interface, and a Bluetooth wireless data transmission module. Moreover, it can perform single fluorescent channel detection of PCR using intercalating dye, followed by a melting curve analysis and loop-mediated isothermal amplification. The proposed compact dual-color qPCR device significantly broadens its potential for POC applications, such as diagnostics or field testing, molecular biology, microfluidics, and virus detection.