








-
David Szlag, Ph.D.
Oakland University
ddPCR is more sensitive than qPCR and it is resistant to inhibition (substances that interfere with the reaction).
Before the COVID-19 pandemic, what was your primary role or field of research?
I was studying environmental DNA (eDNA) and tracking the source of microbes, including cyanobacteria and the toxins they produce, in recreational water.
How severely has your region been impacted by the pandemic?
Southeast Michigan was hit hard in the first wave in April. By the end of September 2020, the region had reported over 75,000 confirmed or probable cases.
How did this wastewater project come about? Who seeded the idea and when?
The project is a cooperative venture between Aquasight LLC, Macomb Public Works, and Oakland University. Aquasight is a private company and they provided the initial catalyst.
What was the primary goal? What did you hope to determine or achieve?
We hope to streamline testing and capture community-level symptomatic and asymptomatic cases by using sewage surveillance.
What Bio-Rad ddPCR platforms did you use to perform your research?
QX200 [Droplet Digital PCR System] and manual drop generation.
Why did you choose to use ddPCR technology to measure SARS-CoV-2?
ddPCR is more sensitive than qPCR and it is resistant to inhibition (substances that interfere with the reaction).
What was the scope of the project — for example, how many people were in the wastewater catchment area?
Our initial project focused on a community of 120,000 people. We have expanded this to include two universities with more than 20,0000 students, another community of 120,000 people, a small community of 20,000 people, and two correctional facilities.
What were the key outcomes/findings from your project?
We looked at the literature to determine to what degree SARS-CoV-2 sheds into wastewater from infected individuals and we examined the clinical case rate in the region. We found that there appears to be five times more cases in southwest Michigan than reported by clinical analyses.
How do you think wastewater testing using ddPCR might help stop the spread of SARS-CoV-2 in different communities?
We have developed a system to rapidly upload our data to a dashboard. Community health officials can use it to track cases, manage testing, make public announcements, manage reopening strategies, and in the future, guide vaccination campaign.
Digital PCR

Bio-Rad's unique Droplet Digital PCR technology provides absolute quantification of nucleic acids for a wide range of applications including cancer mutation studies, HIV quantification, and environmental monitoring.
More Testimonials
Learn how scientists from around the world are monitoring the community-level spread of SARS-CoV-2 through wastewater testing.
Wastewater Surveillance for SARS-CoV-2
Since symptomatic and asymptomatic SARS-CoV-2 infected individuals shed viral RNA in sewer systems, these systems may provide real-time surveillance of SARS-CoV-2 viral spread at the community level, potentially serving as an early warning system to detect COVID-19 outbreaks and prevent further spread of the virus.
Learn More about Wastewater Surveillance for SARS-CoV-2 ยป
Scroll