COVID-19 Virus Environmental Testing: Know What You Are Getting
Make Sense of Your Testing Results
Ever wonder what you are getting when you receive a COVID-19 testing report? Ever wonder how the COVID-19 testing results are generated? Ever wonder what is behind the simple “positive / negative” result report? If so, read along.
Technology advancements are wonderful! Shortly after the COVID-19 disease emerged, the COVID-19 viral genome was sequenced and genetic assays measuring RNA from the virus were designed and published. Now, the RT-PCR technology is the gold standard for clinic diagnostic testing, and also the work horse for COVID-19 virus environmental testing.
Simplicity in reporting is wonderful! As a consumer of the genetic testing results, you should get a simple report of “positive” or “negative”, and/or quantity of viral RNA detected in your sample (usually in the form of copies of viral RNA detected per mass or volume or unit of sample).
Yet, ultimately, you want data probably not just for the sake of having data, but for the purpose of making decisions based on the data. It is important to know what the result is telling you – know what you are getting – given the complexity of the entire testing workflow from collecting a sample to be provided a simple report.
Taking COVID-19 virus testing in wastewater as an example, the chart below is what the testing workflow looks like. Each rectangular box represents a unit process along the testing workflow.
When you get the results, do you find yourself asking these questions?
|Negative||What does this mean – concentration of the virus was lower than certain threshold or was there no virus in my sample? (What is the overall method detection limit for my sample type and matrix? Was there any compound interfering with the detection technology leading to false negatives? How much signal was lost through the complex workflow?)|
|Positive||Any chance of false positive due to cross contamination?|
|Quantification||Any chance of false positive or overestimation due to cross contamination? Any chance of underestimation due to signal loss through the testing workflow, or interference with detection technology from my sample matrix? How consistent are the quantification over time?|
To answer these questions, testing laboratories implement quality control measures. Depending on the expertise and experience of the laboratory in conducting genetic analysis of environmental samples, not all laboratories are aware of the quality controls or how to implement them. Depending on why you are doing COVID-19 virus environmental testing and how you intend to use your results for decision making, some quality controls might be more important than others.
Source Molecular has been fortunate to serve exclusively the niche of environmental testing using genetic technologies for the past 18 years, accumulating extensive experience and expertise in the area. Here are the quality controls we implement, and why we implement them.
To read more about COVID-19 virus environmental testing, visit our blog.