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. 2022 Aug;103(4):115726.
doi: 10.1016/j.diagmicrobio.2022.115726. Epub 2022 May 20.

Application of digital PCR to determine the reliability of Xpert Xpress SARS-CoV-2 assay with envelope (E) gene negative and nucleocapsid (N2) gene positive results

River Chun-Wai Wong  1 , Ann Han Wong  2 , Yolanda Iok-Ieng Ho  2 , Gilman Kit-Hang Siu  3 , Lam-Kwong Lee  3 , Eddie Chi-Man Leung  2 , Raymond Wai-Man Lai  2
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Application of digital PCR to determine the reliability of Xpert Xpress SARS-CoV-2 assay with envelope (E) gene negative and nucleocapsid (N2) gene positive results

River Chun-Wai Wong et al. Diagn Microbiol Infect Dis. 2022 Aug.

Abstract

This study used digital polymerase chain reaction (dPCR) to determine whether envelope (E) gene-negative and nucleocapsid (N2) gene-positive (E-N+) results obtained with the Cepheid Xpert Xpress SARS-CoV-2 assay are reliable. Using droplet digital PCR results as a reference, 18 of 22 E-N+ samples with a low viral load (81.8%) were identified as true positives.

Keywords: Cepheid Xpert Xpress SARS-CoV-2 assay; E gene negative; N2 gene positive; SARS-CoV-2; digital PCR; low viral load.

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Conflict of interest statement

Declaration of competing interest The authors declare that we have no conflicts of interest.

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