Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link
Volume 27, Number 7—July 2021

Multiplex Real-Time Reverse Transcription PCR for Influenza A Virus, Influenza B Virus, and Severe Acute Respiratory Syndrome Coronavirus 2

Bo Shu1, Marie K. Kirby1, William G. Davis, Christine Warnes, Jimma Liddell, Ji Liu, Kai-Hui Wu, Norman Hassell, Alvaro J. Benitez, Malania M. Wilson, Matthew W. Keller, Benjamin L. Rambo-Martin, Yamundow Camara, Jörn Winter, Rebecca J. Kondor, Bin Zhou, Stacey Spies, Laura E. Rose, Jonas M. Winchell, Brandi M. Limbago, David E. Wentworth2, and John R. Barnes2Comments to Author 
Author affiliations: Centers for Disease Control and Prevention, Atlanta, Georgia, USA (B. Shu, M.K. Kirby, W.G. Davis, C. Warnes, J. Liddell, J. Liu, K.-H. Wu, N. Hassell, A.J. Benitez, M.M. Wilson, M.W. Keller, B.L. Rambo-Martin, Y. Camara, J. Winter, R.J. Kondor, B. Zhou, S. Spies, L.E. Rose, J.M. Winchell, B.M. Limbago, D.E. Wentworth, J.R. Barnes); Battelle Memorial Institute, Atlanta (W.G. Davis, J. Liddell); Leidos Inc, Atlanta (Y. Camara)

Main Article

Table 3

Confirmation of established limits of detection of the Influenza SARS-CoV-2 Multiplex Assay*

Viral titer† Influenza A
Influenza B
No. (%) positive Mean Ct ±SD No. (%) positive Mean Ct ±SD No. (%) positive Mean Ct ±SD
102.7 20 (100) 29.71 ±0.51 0 NA 0 NA
20 (100)
33.55 ±1.15


102.9 0 NA 20 (100) 29.80 ±0.74 0 NA

20 (100)
32.70 ±0.48

101.0 0 NA 0 NA 20 (100) 32.59 ±0.78
100.3 0 NA 0 NA 19 (95) 34.71 ±1.03

*Multiplex real-time reverse transcription PCR for influenza A virus, influenza B virus, and SARS-CoV-2. Boldface type indicates limits of detection. Ct, cycle threshold; NA, not applicable; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; SD, standard deviation. †Viral titers are in relation to 50% tissue culture infectious dose, except for B/Colorado/06/2017, which is in relation to 50% egg infectious dose.

Main Article

1These first authors contributed equally to this article.

2These senior authors contributed equally to this article.

Page created: May 13, 2021
Page updated: June 16, 2021
Page reviewed: June 16, 2021
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.