RNA purification human 5 Article 4 Humans 4 SARS-CoV-2 4 COVID-19 3 Severe acute respiratory syndrome coronavirus 2 3 isolation and purification 3 nonhuman 3 procedures 3 virus detection 3 COVID-19 Nucleic Acid Testing 2 RNA directed DNA polymerase 2 RNA extraction 2 RNA, Viral 2 controlled study 2 diagnosis 2 genetics 2 in vitro study 2 limit of detection 2 real time polymerase chain reaction 2 sensitivity and specificity 2 swabbing 2 virology 2 virus RNA 2 2 propanol 1 3' untranslated region 1 5' untranslated region 1 COVID-19 Testing 1 COVID-19 testing 1