SARS-CoV-2 Serology and PCR Testing
Accurate molecular tests for active SARS-CoV-2 infection and subsequent serological tests for the presence of anti-viral antibodies are key tools for fighting the COVID-19 pandemic. PCR-based testing is used to identify infected individuals, and serological testing is necessary to understand the immune response in those who have recovered. Development of specific and sensitive tests of both types (for diagnosis and antibody testing) is a critical need.
Research, development and manufacturing of molecular tests and serology assays is a focus of many laboratories worldwide. Promega provides products and custom services to labs designing, performing and scaling up PCR-based molecular tests, conducting serology tests and researching new serological testing methods.
“Many companies and research teams around the world are working to develop serological assays that can help us in the fight against COVID-19. Any test to be widely deployed must prove both sensitivity and specificity and must have the ability to determine if the antibody level is actually protective for the patient.”
- Ash Anderson, Promega Chief Medical Officer
PCR-Based SARS-CoV-2 Testing Methods
RT-qPCR based assays designed to amplify SARS-CoV-2-specific sequences are the primary method currently used for detection of active infections. Tests are available targeting various unique SARS-CoV-2 sequences in the N, E, S and RdRp sequences (3,10). RT-qPCR tests that use two or more targets are likely to have higher specificity.
The World Health Organization (WHO) has published summary information for a few protocols including the United States recommended protocol (11). The CDC recommends using the CDC 2019-Novel Coronavirus (2019-nCoV) Real-Time RT-PCR Diagnostic Panel for primary diagnosis, which includes primers and probes for different regions of the nucleocapsid (N) gene plus an additional primer/probe set for detection of RNase P (RP) gene in control/clinical samples (12,13).
Other organizations have released their own kits. On February 25 2020, Promega was recognized by Co-Diagnostics, Inc. for support in manufacturing the new Logix Smart™ COVID-19 Test, which received CE mark approval and is available in Europe as an in vitro diagnostic.
“Promega is proud to support the CDC’s rapid response efforts and COVID-19 testing labs with approved amplification technology"
Sanger Sequencing for SARS-CoV-2 Research
Sanger sequencing can complement other techniques for research and variant detection of SARS-CoV-2. From smaller-scale projects to confirmation of NGS results, Sanger sequencing is considered the gold standard and most widely used DNA sequencing method.
This application note provides an example protocol for sequencing a region of the SARS-CoV-2 genome using the ProDye™ Terminator Sequencing System with analysis by capillary electrophoresis on the Spectrum Compact CE System.
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CDC 2019-Novel Coronavirus (2019-nCoV) Real-Time RT-PCR Diagnostic Panel. Accessed May 13, 2020. https://www.fda.gov/media/134922/download.
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