By Travis Swaggard
I am a Senior Biologist working for a Repository in Manassas VA that stores and handles various microorganisms, media products, and cell lines. We also grow and culture viruses, that now include SARS-CoV-2, to develop products that can be sold to clinical laboratories, academia, and pharmaceutical companies for biomedical research and diagnostic testing. My work since COVID-19 became a pandemic and a serious threat to global health has focused almost entirely on testing different regions of the SARS-CoV-2 genome from synthetically derived sections of the virus. This is done using the same technique used to screen clinical samples in hospitals and laboratories, known colloquially in our field as qPCR, or quantitative polymerase chain reaction. This is the same methodology used in the testing kits provided by the CDC. Most undergraduate molecular biology students (and, perhaps even high schoolers specializing in AP biology coursework) should understand this technique fairly well: using the same principles of traditional PCR, a region of DNA (or RNA, in the case of SARS-CoV-2) is targeted using specialized primers that complement the RNA sequence. From there, under specific temperatures, a polymerase enzyme will add nucleotides using the primers as a guide. A special molecular probe is also included that will emit fluorescence, but only when the enzyme has completed polymerization of the target region of RNA.
This cycle is then repeated 25-50 times to generate an exponential number of copies of the original target RNA, creating a brighter fluorescent signal that is then detected by a machine which translates the light into an electrical signal which can be analyzed using software. These RNA standards can be used as controls for any qPCR assays performed in a clinical diagnostic or research setting. Fortunately, the material is synthetically derived and contains only a small piece of the genome, rather than the whole encapsulated virus, so it can’t cause infection. Therefore, my work can be done within BSL-2 biosafety conditions whileSARS-CoV-2 live virus has to be handled in BSL-3 or higher. These synthetically derived standards are important for researchers because they don’t require the need to culture live viruses in the laboratory and thereby eliminate the risk of infection. Most of my work circulates around quality control, so I am using rigorous qPCR testing to ensure that the material we produce on a mass scale, such as SARS-CoV-2 RNA, is being sold as advertised. . We haven’t had any major issues with any of our internally designed synthetic standards yet. These items are widely used in the fight against the spread of COVID-19, from clinical laboratories testing patient samples to a major university labs and pharmaceutical companies trying to come up with a vaccine against the virus as quickly as possible.