Isothermal amplification-based assays for rapid and sensitive detection of severe acute respiratory syndrome coronavirus 2: Opportunities and recent developments.

The coronavirus disease 2019 (COVID-19) is a global pandemic caused by a novel coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To date, the virus has been detected in 219 countries of the world. Therefore, managing the disease becomes the priority, in which detecting the presence of the virus is a crucial step. Presently, real-time RT polymerase chain reaction (RT-qPCR) is considered a gold standard nucleic acid amplification test (NAAT). The test protocol of RT-qPCR is complicated, places high demands on equipment, testing reagents, research personnel skills and is expensive. Therefore, simpler point-of-care (POC) tests are needed to accelerate clinical decision-making and take some of the workload from centralized test laboratories. Various isothermal amplification-based assays have been developed for the sensitive detection of different microorganisms, and recently some of them have been applied for detection of SARS-CoV-2. These do not require any programable thermocycler, can produce the results in a single temperature, and therefore, are considered simple. Unlike RT-qPCR, these methods are highly sensitive, specific, less time-consuming, simple and affordable, and can be used as POC diagnostic kit for COVID-19. In this review, we have discussed the potential of isothermal amplification-based assays as an alternative to RT-qPCR for the detection of SARS-CoV-2.