ABSTRACT
Coronavirus disease 2019 (COVID-19) has been a pandemic for more than a year.With the expanding second wave of the pandemic in winter,the continuous evolution of SARS-CoV-2 has brought new issues,including the significance of virus mutations in infection and the detection of asymptomatic infection.In this review,we first introduced several major SARS-CoV-2 mutations since the COVID-19 outbreak and then mentioned the widely used molecular detection techniques to diagnose COVID-19,primarily focusing on their strengths and limitations.We further discussed the effects of viral genetic variation and asymptomatic infection on the molecular detection of SARS-CoV-2 infection.The review finally sum-marized useful insights into the molecular diagnosis of COVID-19 under the special situation being challenged by virus mutation and asymptomatic infection.