Detection of SARS-CoV-2 is comparable in clinical samples preserved in saline or viral transport media

Radbel, Jared; Jagpal, Sugeet; Roy, Jason; Brooks, Andrew; Tischfield, Jay; Sheldon, Michael; Bixby, Christian; Witt, Dana; Gennaro, Maria Laura; Horton, Daniel B.; Barrett, Emily S.; Carson, Jeffrey L.; Panettieri, Reynold A.; Blaser, Martin J.

As the COVID-19 pandemic sweeps across the world, the availability of viral transport media (VTM) has become severely limited, contributing to delays in diagnosis and rationing of diagnostic testing. Given that SARS-CoV-2 viral RNA has demonstrated stability, we posited that phosphate buffered saline (PBS) may be a viable transport medium, as an alternative to VTM), for clinical qPCR testing. We assessed the intra- and inter-individual reliability of SARS-CoV-2 qPCR in clinical endotracheal secretion samples transported in VTM or PBS, evaluating the stability of the RT-qPCR signal for three viral targets (N gene, ORF1ab, and S gene) when samples were stored in these media at room temperature for up to 18 hours. We report that using PBS as a transport medium has high intra-and inter-individual reliability, maintains viral stability, and is comparable to VTM in the detection of the three SARS-CoV-2 genes through 18 hours of storage. Our study establishes PBS as a clinically useful medium that can be readily deployed for transporting and short-term preservation of specimens containing SARS-CoV-2. Use of PBS as a transport medium has the potential to increase testing capacity for SARS-CoV-2, aiding more widespread screening and early diagnosis of COVID-19.