Ann Clin Microbiol 2020;23:165-171. Experience at Department of Laboratory Medicine during the COVID-19 Outbreak in Daegu

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Table 1. Criteria for the interpretation of SARS-CoV-2 molecular tests in the confirmed patients
Ct values for:Interpretation (1st Ed)Interpretation (5th Ed)
ERdRpNIC
<40<40<40<40PositivePositive
<40<40<40≥40PositivePositive
≥40≥40≥40<40NegativeNegative
≥40<40<40≥40Repeat (Seegene)Repeat after reextraction (Seegene)
<40≥40<40   
<40<40≥40   
≥40≥40<40   
≥40<40≥40   
<40≥40≥40   
≥40≥40≥40   
≥40<40<40<40IndeterminateIndeterminate
<40≥40<40   
<40<40≥40   
≥40≥40<40   
≥40<40≥40   
<40≥40≥40   

Abbreviations: Ct, cycle of threshold; E, envelope gene; RdRp, RNA-dependent RNA polymerase gene; N, nucleocapsid gene; IC, internal control.