Modular micro-PCR system for the onsite rapid diagnosis of COVID-19
Phuong Quoc Mai Nguyen, Ming Wang, Nelisha Ann Maria, Adelicia Yongling Li, Hsih Yin Tan, Gordon M. Xiong, Meng-Kwang Marcus Tan, Ali Asgar S. Bhagat, Ong C, Chwee Teck Lim
Abstract
Effective containment of the COVID-19 pandemic requires rapid and accurate detection of the pathogen. Polymerase chain reaction (PCR) remains the gold standard for COVID-19 confirmation. In this article, we report the performance of a cost-effective modular microfluidic reverse transcription (RT)-PCR and RT-loop mediated isothermal amplification (RT-LAMP) platform, Epidax®, for the point-of-care testing and confirmation of SARS-CoV-2. This platform is versatile and can be reconfigured either for screening using endpoint RT-PCR or RT-LAMP tests or for confirmatory tests using real-time RT-PCR. Epidax® is highly sensitive and detects as little as 1 RNA copy per µL for real-time and endpoint RT-PCR, while using only half of the reagents. We achieved comparable results with those of a commercial platform when detecting SARS-CoV-2 viruses from 81 clinical RNA extracts. Epidax® can also detect SARS-CoV-2 from 44 nasopharyngeal samples without RNA extraction by using a direct RT-PCR assay, which shortens the sample-to-answer time to an hour with minimal user steps. Furthermore, we validated the technology using an RT-LAMP assay on 54 clinical RNA extracts. Overall, our platform provides a sensitive, cost-effective, and accurate diagnostic solution for low-resource settings.