Ammonium Sulfate Addition Reduces the Need for Guanidinium Isothiocyanate in the Denaturing Transport Medium Used for SARS-COV-2 RNA Detection

Rapid identification of SARS-CoV-2 infected individuals through viral RNA detection followed by effective personal isolation remains the most effective way to prevent the spread of this virus. Large-scale RNA detection involves mass specimen collection and transportation. For biosafety reasons, denaturing viral transport medium has been extensively used during the pandemic. But the high concentrations of guanidinium isothiocyanate (GITC) in such media have raised issues around sufficient GITC supply and laboratory safety. Here, we tested whether supplementing media containing low concentrations of GITC with ammonium sulfate (AS) would affect the throat-swab detection of SARS-CoV-2 pseudovirus or a viral inactivation assay targeting both enveloped and non-enveloped viruses. Adding AS to the denaturing transport media reduced the need for high levels of GITC and improved SARS-COV-2 RNA detection without compromising virus inactivation.