Pre-analytical sample stabilization by different sampling devices for PCR-based COVID-19 diagnostics.

The outbreak of the SARS-CoV-2 pandemic created an unprecedented requirement for diagnostic testing, challenging not only healthcare workers and laboratories, but also providers. Quantitative RT-PCR of various specimen types is considered the diagnostic gold standard for the detection of SARS-CoV-2, both in terms of sensitivity and specificity. The pre-analytical handling of patient specimens is a critical factor to ensure reliable and valid test results. Therefore, the effect of storage duration and temperature on SARS-CoV-2 RNA copy number stability was examined in various commercially available specimen collection, transport and storage devices for naso/oropharyngeal swabs and saliva. The swab specimen transport and storage devices tested showed no significant alteration of viral RNA copy numbers when stored at room temperature, except for one system when stored for up to 96 h. However, at 37 °C a significant reduction of detectable RNA was found in 3 out of 4 of the swab solutions tested. It was also found that detectability of viral RNA remained unchanged in all 7 saliva devices as well as in unstabilized saliva when stored for 96 h at room temperature, but one device showed marked RNA copy number loss at 37 °C. All tested saliva collection devices inhibited SARS-CoV-2 infectivity immediately, whereas SARS-CoV-2 remained infectious in the swab transport systems examined, which are designed to be used for viral or bacterial growth in cell culture systems. • Raised temperature has major impact on SARS-CoV-2 RNA stability in 3 of 4 swab systems and 1 of 7 saliva collection devices. • SARS-CoV-2 RNA stability should be tested in specimen collection/transport/storage devices at level close to detection limit. • Tested saliva collection devices inactivate SARS-CoV-2. • Tested swab systems do not inactivate SARS-CoV-2. [ABSTRACT FROM AUTHOR]