By Arvind Kothandaraman
General Manager, Specialty Diagnostics, PerkinElmer
Finding the right solution for your coronavirus testing needs can be a difficult decision. In this article, we address the critical factors that organizations should consider when incorporating a new SARS-CoV-2 testing workflow into their lab.
The most common methods used for SARS-CoV-2 testing and screening are:
- Nucleic acid detection assays—to detect SARS-CoV-2 viral particles
- Antibody detection assays—to detect antibodies (e.g., IgM, IgG) developed to the SARS-CoV-2 virus
Real-time PCR assays are used to identify SARS-CoV-2 RNA shed by individuals with an active infection. The results are typically used to determine treatment and quarantine plans. On the other hand, immunoassays detect antibodies to SARS-CoV-2 that have been reported to appear days after infection and persist for a relatively longer time.1 Immunoassays are valuable tools for identification of individuals who have developed an adaptive immune response and for disease surveillance. Depending on the desired outcome, one or more complementary detection methods can be employed.
The viral dynamics of SARS-CoV-2 is not yet fully understood. There is evidence that viral load tends to correlate with the severity of infection.2 Reports also suggest the possibility of SARS-CoV-2 transmission from persons who are presymptomatic or asymptomatic.3 A highly sensitive diagnostic assay with the ability to detect low viral load is required to accurately detect virus or antibodies and assist in preventing the spread of infection. Automation and assay controls are effective tools to ensure robust results.
SARS-CoV-2 testing is performed on samples taken from the human body, such as swabs of mucus from inside the nose or back of the throat, or blood taken from a vein or fingerstick. Most of the SARS-CoV-2 real-time RT-PCR assays use either oropharyngeal or nasopharyngeal swab samples while the immunoassays rely on blood samples. Dried blood spots (DBS) are an attractive alternative sample type for SARS-CoV-2 antibody testing because dried blood samples can be easily collected and shipped to a laboratory for analysis.
Availability of reagents and equipment
Vendors with a steady supply chain and a transparent view into product availability should be prioritized. Materials can be directly sourced from manufacturers who meet these criteria or from organizations such as the International Reagent Resource (IRR) that source from manufacturers and supply at no cost U.S. public health labs and other eligible organizations.
Testing capacity can be increased by adding automation, additional shifts, or hiring more employees. Increasing employees’ workload is not an attractive long-term solution to increasing testing throughput, and hiring new employees who can learn the lab processes quickly can be difficult even in the best of times. Modular, scalable automation can help labs adapt to variable sample throughput and eliminate most human handling steps, which are a primary source of run-to-run variation, improving reproducibility and accuracy.
Testing is a complex, multistep process. Suppliers offering a comprehensive, ready-made solution to implement automated SARS-CoV-2 testing can
simplify this process. Consolidation to a single vendor which can supply all of the needed workflow components can improve procurement efficiency and visibility to availability status of reagents, equipment, and consumables.
The quality of support can be the difference between success and failure. A responsive support team can help guarantee a better experience by assisting in every step along the way from installation to analysis. Labs should work with suppliers they trust.
1. Interim Guidelines for COVID-19 Antibody Testing. (2020, May 23). Retrieved July 19, 2020.
2. Huang, J., Ran, R., Lv, Z., Feng, L., Ran, C., Tong, Y., . . . Li, Y. (2020). Chronological Changes of Viral Shedding in Adult Inpatients with COVID-19 in Wuhan, China. Clinical Infectious Diseases. doi:10.1093/cid/ciaa631.
3. Wei, W. E., Li, Z., Chiew, C. J., Yong, S. E., Toh, M. P., & Lee, V. J. (2020). Presymptomatic Transmission of SARS-CoV-2 — Singapore, January 23–March 16, 2020. MMWR. Morbidity and Mortality Weekly Report, 69(14), 411-415. doi:10.15585/mmwr.mm6914e1.
Learn more to overcome your SARS-CoV-2 challenges perkinelmer-appliedgenomics.com.