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Comment
. 2021 Mar;82(3):414-451.
doi: 10.1016/j.jinf.2020.10.017. Epub 2020 Oct 24.

Ct values from SARS-CoV-2 diagnostic PCR assays should not be used as direct estimates of viral load

Elias Dahdouh  1 , Fernando Lázaro-Perona  1 , María Pilar Romero-Gómez  1 , Jesús Mingorance  2 , Julio García-Rodriguez  1
Affiliations
Comment

Ct values from SARS-CoV-2 diagnostic PCR assays should not be used as direct estimates of viral load

Elias Dahdouh et al. J Infect. 2021 Mar.

Abstract

Image, graphical abstract

Keywords: C(t); COVID-19; SARS-CoV-2; qPCR.

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Figures

Image, graphical abstract
Graphical abstract
Fig 1
Fig. 1
Analysis of the SARS-CoV-2 Ct values obtained using a commercial RT-qPCR assay (Vircell) in a set of clinical samples. A) Cts of the Internal Control RNA plotted against the SARS-CoV-2 N gene Cts (r2 = 0.004). B). Cts of the human RNAse P plotted against the SARS-CoV-2 E gene Cts (r2 = 0.007). C) Normalized SARS-CoV-2 gene E Ct values (log(2−ΔCt)=log(2−Cttarget-Ctreference)) plotted against the SARS-CoV-2 E gene. The normalized Ct values are relative loads (ratios of viral target to human target) and are transformed to logarithmic scale for graphical representation. The black arrow illustrates the broad range spanned by any particular Ct value.
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Comment on

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