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. 2021 Mar 4;11(3):438. doi: 10.3390/diagnostics11030438

Table 2.

Comparison of the results of cycle threshold (Ct) values obtained by RT-qPCR and time to positivity (Tp) values obtained by RT-LAMP assays using primer sets ORF1ab, N5, N15, and E in testing 20 RNA isolates from COVID-19 patients. Groups of samples, commercial Real-Time PCR Detection Kits targeting ORF1ab and E/N used in RT-qPCR tests, and primer sets evaluated for RT-LAMP assays are indicated. Ct and Tp values are indicated in minutes.

RT-qPCR
Ct Values		 Real-Time RT-LAMP
Tp Values
Groups No. Sample Commercial Kit 1 ORF1ab E/N ORF1ab N5 N15 E
Group 1
ORF1ab+
(Ct < 30)
E/N+		 1 VIASURE 22 27 15 14 9 27
2 COBAS 25 26 18 16 13 72
3 VIASURE 25 29 15 15 19 43
4 VIASURE 26 25 17 16 11 28
5 VIASURE 27 31 17 18 13 -
6 VIASURE 27 30 19 18 13 35
Group 2
ORF1ab+
(Ct > 30)
E/N+		 7 VIASURE 32 31 20 22 13 60
8 COBAS 32 35 35 23 49 -
9 VIASURE 33 39 23 20 39 -
10 COBAS 33 36 31 - 60 -
11 COBAS 34 36 - - 45 -
12 VIASURE 39 36 - - 36 -
Group 3
ORF1ab+
E−		 13 COBAS 36 - 39 - 29 -
14 COBAS 33 - 30 18 47 -
Group 4
ORF1ab-
N+		 15 VIASURE - 25 34 - 46 -
16 VIASURE - 38 28 - 31 -
17 VIASURE - 38 - - - -
18 VIASURE - 40 43 - 60 -
19 VIASURE - 41 - - 58 -
20 VIASURE - 41 - - 30 -

1 A different commercial kit for RNA extraction was used to perform RT-qPCR using the commercial Real-Time PCR Detection Kits. NUCLISENS EASYMAG, BIOMÉRIEUX, France, for VIASURE SARS-CoV-2 Real-Time PCR Detection Kit, CERTEST BIOTECH, Spain; an integrated system in an automated platform for COBAS 6800, ROCHE, Switzerland, following manufactures’ instructions.