Hybrid Opto-Thermocycler for RT-qPCR Detects SARS-CoV-2

Although real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) is the gold standard for detecting the virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other pathogens, the coronavirus disease 2019 (COVID-19) pandemic has highlighted the scarcity of instruments, devices, and reagents for polymerase chain reaction (PCR) testing in constrained settings. At least for under-resourced countries, it has become critical to deploy instruments that can be rapidly constructed and satisfy this demand. Instead of separating the optical system from the thermal module (typical of qPCR thermocyclers), we report a portable Hybrid Opto-Thermocycler-dubbed HybOT Cycler-that takes advantage of the high-temperature tolerances (>100 degrees C) of electronic and optical components to combine thermal control, illumination, and fluorescence detection into a highly integrated hybrid module. This simple configuration allowed us to reduce the overall number of components, thus simplifying its assembly and reducing the instrument size. The HybOT Cycler is wirelessly controlled from an application installed in a tablet. PCR assays are carried out in a bubble-free microfluidic device that can be easily replicated from an acrylic mold. Using the HybOT Cycler, down to 100 copies/mu L of genetic material of the virus SARS-CoV-2 with 95% sensitivity and 100% specificity is detected. The HybOT Cycler can assist in diagnosing SARS-CoV-2 and other pathogens in resource-poor settings.