The Comparative Analysis of Two RT-qPCR Kits for Detecting SARS-CoV-2 Reveals a Higher Risk of False-Negative Diagnosis in Samples with High Quantification Cycles for Viral and Internal Genes

Figure 4

Impact of the TAAG diagnostic kit on the detection of SARS-CoV-2 variants. Twelve previously diagnosed SARS-CoV-2 positive samples by Thermo Fisher kit were randomly chosen and analyzed for the presence of SARS-CoV-2 variants by RT-qPCR. (a) Cq values for detected SNV probes associated with SARS-CoV-2 variants (N501Y, K417 N/T, E484 K, Hv 69/70 del, and/or P681H). When only the original SARS-CoV-2 variant was detected, it was denoted with triangles (▲). When the Gamma variant sample (N501Y, K417 N/T and E484 K probes positive amplification) was detected, it was denoted with squares (■). The other six samples showed no amplification for any of the SNV probes tested. (b) Summary of the diagnostic impact of the TAAG (N1 and E genes) and Thermo Fisher (ORF1ab gene) on the detection of SARS-CoV-2 variants.

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