What to Consider When Choosing a SARS-CoV-2 Real-Time RT-PCR Assay

Accurate detection of SARS-CoV-2 is critical for both patient treatments, as well as control of the COVID-19 pandemic. Many factors need to be considered when choosing a workflow to use for SARS-CoV-2 detection.

Assay Specificity

Accuracy or specificity is the ability to determine a negative case (specificity). Comparisons of commercially available real-time RT-PCR SARS-CoV-2 tests have generally concluded that they have similar accuracy. Therefore, considerations such as sensitivity, availability, throughput, labor requirements, and cost need to be considered when choosing a testing workflow.

Assay Sensitivity

The sensitivity of a laboratory test determines its ability to detect a positive case. To learn how lower Limits of Detection (LOD) reduces the reporting of false-negative results, read our blog post, The Importance of Sensitivity in SARS-CoV-2 Real-Time RT-PCR Assays.

Reagent Availability

Availability of reagents and equipment needed for SARS-CoV-2 testing has become a critical factor that needs to be considered when choosing a solution to implement in your lab. Shortages of nucleic acid isolation reagents along with RT-PCR assays and the equipment needed to automate them have been responsible for slowing down labs ability to do testing. This can be harder to determine if multiple companies supply these components. Single source workflows simplify the ordering processes and ensure you have visibility to availability of all the workflow components.

Throughput and Labor Requirements

Throughput and labor requirements are other important factors to consider. Automated solutions help laboratories handle large numbers of samples and can be scaled to keep pace with fluctuating demand without requiring increasing the number of employees. Automation also minimizes the risk of laboratory-acquired infections during high volume processing. The steps of the SARS-CoV-2 real-time RT-PCR workflows which can be automated include:

  • Sample reformatting and setup for nucleic acid isolation
  • Nucleic acid isolation
  • Set-up of PCR assay
  • Sample Tracking

Data Analysis

Complicated qPCR systems and multiplex RT-PCR assays can be information overload.  When there are simple data analysis solutions available, sample to result determination can be done with almost no effort.  An easy to use Excel Macro can be configured to each laboratory’s needs and makes the huge amount of data configurable to a single report.

Reducing Complexity for US Public Health Labs

Costs to consider when implementing a solution include both capital equipment costs and reagent costs. These costs can vary greatly depending upon workflow and throughput. Initial capital expenses needed to set up high throughput labs can be daunting. To help offset these costs look for single source companies which offer reagent rental-based solutions.

Alternatively, organizations such as the International Reagent Resource (IRR) supplies RNA extraction kits, SARS-CoV-2 RT-PCR kits, enzymes, and consumables to US public health laboratories at no cost. Read our recent blog post, The IRR: Helping Labs Test for COVID-19, for more information about how the IRR helps offset these costs for US public health laboratories.

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