SARS-CoV-2 Viral RNA Extraction From Human Saliva Samples With NAB Nanosep® Centrifugal Devices

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent of the global pandemic of coronavirus disease 2019 (COVID-19). SARS-CoV-2 is transmitted from person-to-person through spreading of droplets and aerosols. Both nasopharyngeal swabs and saliva have been in use for diagnosing SARSCoV-2 infection status.

Here we evaluate the performance of the Pall NAB Nanosep centrifugal device for the isolation of SARS-CoV-2 viral RNA from human saliva samples spiked with heat inactivated virus using reagents (RCOM1 and RCOM2) from two commercially available kits for extraction of viral RNA. The CDC RT-PCR assay for SARS-CoV-2 detection^1,2 was used to evaluate the NAB Nanosep devices and their performance was compared against devices of the respective commercial reagent manufacturer (DCOM1 or DCOM2) and a centrifugal device that is commercially available without reagents (DCOM3).

The NAB Nanosep devices allowed reliable detection of the viral nucleocapsid gene sequences (N1 and N2) and of the human RNase P gene (RP) that are interrogated with the assays after extraction with both reagents RCOM1 and RCOM2. Average Ct values and Ct value distributions observed with the NAB Nanosep samples were similar to those of the benchmarked commercially available devices.