Waterra eDNA Filters for Water Sampling

Waterra eDNA Filters are manufactured  in our clean room facility in Calgary, Alberta, Canada. Each filter is individually bagged with two end caps to contain a buffer for sample preservation. Filter media is available in 5 different pore sizes from 0.1 to 5 micron and offered in 300 and 600 square centimetre formats.

Background Information

There is interest in querying some surface water bodies as to the presence of certain organisms. Perhaps an invasive species has been noted and one wants to determine its presence. Surface water bodies such a ponds, streams and lakes can be sampled using Waterra eDNA filters by pumping water from that body through the filter. DNA in the water is captured by the filter and can be preserved for extraction in a laboratory setting.

The “e” in eDNA stands for Environmental and “DNA” is Deoxyribonucleic Acid, well known to be the building block of life. DNA is contained in every living organism’s cells and is shed into the environment in many ways. The organism may live or lived in the water body or catchment area, was passing through or was transported in. Irrespective of how it got there, if it is in the water there is a chance that the DNA could be in the water sample processed through the eDNA filter.

An advantage of using Waterra eDNA filters is that the large surface area of the filter (either 300 cm² or 600 cm²) allows large volumes of water to be run through. Samples up to 100 litres or more, depending on the turbidity of the water increase the odds of capturing eDNA of the target species. Processing large samples becomes challenging unless one uses a pump.

Sample Collection Techniques:

Simply plug a Waterra eDNA filter into your suction pump tubing and place the filter inlet end into the water body to be sampled. Run the designated volume of water through the inline disposable filter capturing particulate matter including eDNA in the filter.

Waterra offers battery-operated peristaltic pumps which were designed for field use. We recommend that the peristaltic tubing be connected to another length of LDPE or HDPE tubing which in turn has a filter installed at the end. By connecting the filter at the intake end, the length of PE tubing and the peristaltic tubing itself do not contact the captured eDNA. This mitigates the need to change out the tubing for each sample.

If this is not practical, then the filter can be inserted between the peristaltic tubing and a disposable length of tubing which should be changed out after every sample location. Waterra provides a complete system of pump, tubing, eDNA filters for such sampling.

Once the desired volume is processed, the filter is carefully drained from the outlet side so as not to loss particulate captured in the filter. A buffer solution is typically added to preserve the eDNA although freezing and drying are alternate preservation methods. Fit on a Buffer end cap tightly on the inlet side. Fill the filter with the desired buffer to preserve the DNA and fit the second Buffer end cap to trap the Buffer in the filter. The Waterra end plugs retain the buffer and eDNA for further processing.  End plugs are provided in each sealed eDNA filter bag.

We wrote an article  here  published in Environmental Science & Engineering Magazine as an introduction of the concept of eDNA sampling with special reference to an outstanding treatise on the subject “Environmental DNA for Biodiversity Research and Monitoring” by Pierre Taberlet, Aurélie Bonin, Lucie Zinger, and Eric Coissac published by Oxford University Press in 2018.

Method 1 to insert buffer

Method 2 to insert buffer. Some Researchers find this more effective.