“Background: The detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA by reverse-transcription polymerase chain reaction (PCR) does not necessarily indicate shedding of infective virions. There are limited data on the correlation between the isolation of SARS-CoV-2, which likely indicates infectivity, and PCR...
Methods: … No clinical samples with PCR Ct values >32 resulted in positive viral cultures...
Results: The highest Ct for the N gene target in any clinical sample where SARS-COV-2 was successfully cultured was 32. Based on this result and the Ct cutoff value of 37 determined by PCR of TCID dilutions and incorporating a 1-log margin of error, we were confident that any clinical sample with a Ct of ≥37 was not indicative of viable virus.”
© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. Personal use Individuals accessing OUP journals content may view, reproduce, or store copies of such content provided that it is used only for personal, non-commercial use. Any use of such content in whole or in part must include the bibliographic citation, including author attribution, date, article title, journal title, and URL and MUST include a copy of the copyright notice. Source: https://academic.oup.com/pages/standard-publication-reuse-rights