Tergitol-15-S-9 inactivates SARS-CoV-2 and boosts immunoassay signals

METHOD SUMMARY Treatment of SARS-CoV-2 virus lysate or patient specimens in viral transport medium with 0.1-0.5% Tergitol 15-S-9 for 10 min inactivates the virus, as measured by infectivity in cell culture, and does not interfere with detection of the SARS-CoV-2 nucleocapsid by a prototype nucleocapsid antigen immunoassay run on the automated ARCHITECT platform. Inactivation of SARS-CoV-2 virus is necessary to mitigate risk but may interfere with diagnostic assay performance. We examined the effect of heat inactivation on a prototype SARS-CoV-2 antigen immunoassay run on the ARCHITECT automated analyzer. Recombinant full-length SARS-CoV-2 nucleocapsid protein and virus lysate detection was reduced by 66 and 31%, respectively. Several nonionic detergents were assessed as inactivation alternatives based on infectivity in cultured Vero CCL81 cells. Incubation of SARS-CoV-2 in 0.1% Tergitol 15-S-9 for 10 min significantly reduced infectivity and increased the immunoassay signal for cultured lysate and patient specimens. Tergitol 15-S-9 can inactivate SARS-CoV-2 while preserving epitopes on the nucleocapsid protein for enhanced detection by immunoassay antibodies.