Environment New DNA detector detects amphibians in water samples

Using forensics to combat species extinction: Swiss researchers have developed DNA detectors to identify amphibians in water samples. The detector performed well in initial tests of the new technology in the canton of Aargau, the WSL announced on Tuesday.

According to the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), more species were detected with the DNA detector during a single visit than during three traditional monitoring visits. It is important to observe how the population and distribution of amphibians changes over time in order to better protect the animals.

Traditionally, amphibians are monitored by experts who visit the animals' breeding sites and record the species they see or hear. For the new DNA detector, the researchers instead collect water samples and search for traces of amphibian genes in them. This method is not new in itself. However, the analysis of this so-called environmental DNA was previously expensive and it took a long time before results were available.

No sequencing necessary

To solve this problem, the WSL researchers, together with researchers from the Swiss Federal Institute of Technology in Zurich, have developed a method they have named "ampliscanning". In a first step, the DNA present in the water is copied several times to make it easier to detect. The researchers then add special molecular detectors to the sample. These detectors were developed in such a way that they fluoresce, i.e. light up, when they come into contact with certain DNA.

This allows the researchers to search for seven different Swiss amphibian species without time-consuming and costly gene sequencing, according to the WSL.