Environmental Water DNA Extraction

A 10 L sample of collected environmental water was passed through a 47 mm GF/D (2.7 μm pore size) glass-fibre filter (Whatman). After filtering the samples, the filters were fixed by adding 15 mL of ethanol^{46 (link)}. The filter was divided into two equal parts with scissors before DNA extraction; one of the two pieces was used for DNA extraction in order to properly fit the extraction kit. DNA extraction from the filter was performed using a DNeasy Blood & Tissue Kit^{47 (link)}. The extracted eDNA was eluted in 400 µL (twice with 200 µL) of buffer AE supplied with the kit. The extracted eDNA was quantified using a Qubit 2.0 Fluorometer (Thermo Fisher Scientific) and subjected to PCR under the same conditions as used for Sanger sequencing to confirm PCR amplification.