Table 3. Comparison of frequency and Ct and peak value of amplification curves of positive target genes in inconclusive results between COVID-19 cases and non-COVID-19 cases

Ann Clin Microbiol 2020;23:191-199. Causes and Clinical Relevance of Inconclusive SARS-CoV-2 Real-Time Reverse TranscriptionPCR Test Results

Table 3. Comparison of frequency and Ct and peak value of amplification curves of positive target genes in inconclusive results between COVID-19 cases and non-COVID-19 cases

Target gene	COVID-19 cases				Non-COVID-19 cases
Target gene	No. (%)	No. (%) of Ct ≥ 33	Ct, M ± SD	Peak RFU, M ± SD	No. (%)	No. (%) of Ct ≥ 33	Ct, M ± SD	Peak RFU, M ± SD
E	4 (8.2)	4 (100)	35.2±1.9	226.4±22.6	13 (29.5)	9 (69.2)	35.3±3.1	420.9±288.5
RdRp	11 (22.4)	11 (100)	37.2±1.4	363.8±109.4	27 (61.4)	27 (100)	37.7±1.0	442.5±254.9
N	16 (32.7)	16 (100)	38.1±1.4	460.0±212.3	4 (9.1)	4 (100)	39.3±0.3	567.1±110.0
E + RdRp	2 (4.1)	2 (100)	36.0±1.2	365.9±23.9	0	0	N/A	N/A
			36.3±1.1	1223.3±523.6
E + N	9 (18.4)	9 (100)	34.6±1.8	383.8±124.8	0	0	N/A	N/A
			37.2±1.7	538.1±193.6
RdRp + N	7 (14.3)	7 (100)	37.0±1.5	573.3±342.4	0	0	N/A	N/A
			37.7±1.1	481.5±121.7

Abbreviations: COVID-19, coronavirus disease 19; Ct, cycle threshold; M, mean; SD, standard deviation; RFU, relative fluorescence unit; N/A, not applicable/available; E, envelope gene; RdRp, RNA-dependent RNA polymerase gene; N, nucleocapsid gene.