PolyWAG (Water Acquired Genomics) System: A Field Programmable and
Customizable Auto-sampler for eDNA
Organisms leave traces of DNA as they move through their environments.
The extraction of these DNA traces is known as environmental DNA (eDNA).
eDNA provides scientists and researchers a non-invasive, rapid,
cost-effective and sensitive way to detect and quantify species.
Traditional eDNA sampling consists of manually filtering water, which is
labor and cost-intensive for remote locations. Furthermore,
commercialized solutions are expensive and require a field operator.
This eDNA sampler project aims to provide an affordable, open-sourced,
remotely deployable, fully automated, and customizable alternative. The
PolyWAG (Water Acquired Genomics) system can run up to 24 inline filter
units with support for different conditions including pressure, time and
volume limit. The pumps deliver maximum 400mL/min with solenoid valves
separating each inline filter to minimize cross-contamination. At the
end of each sample, the desired stabilizing solution can be injected to
fully submerge the filter for preservation. An optional river depth
sensor can provide a proxy for flow to correct eDNA concentrations to
allow for improved quantification of organisms. Data acquired during
operation including water depth, pressure, temperature, and flow rate
will be stored on microSD card in CSV format, which allows easier data
export and analysis. A web application provides an intuitive UI for
in-field programming, real-time sensor updates, scheduling tasks, and
manual operations. We present data from multiple tests showing the
length of the preservation period and the contamination level between
samples. The PolyWAG system is estimated to be $3000 each, with add-on
river depth sensor and 10ah 12V battery.