Experiment for increasing eDNA detections

Surface water from off Hokkaido was sampled following methods shown above video, and stored in six of 10 L-tank as evenly as possible.

We tried to increase detections of eDNA with the experimental design described below.

In present study, we hypothesized that the oceanic water is comparably clear and does not contain any materials so eDNA cannot attach.

And this may cause the low detection rate that eDNA pass through the filter cartridge.

Therefore we added four materials (sediment, diatomite, zicronia bead, molecular sieve) during filtration, and tried 0.22 um pore size filter in comparison with 0.45 um filter, expecting a higher detection rate.

Each experimental treatment had 5 replicates with 2-L filtered samples.

The experiment was conducted twice in summer and winter, and the results differed by season.

In the summer trial, Exp4 which added diatomite was significantly higher than others, while Exp5 which added zirconia bead was the highest in the winter trial.

From the result of GLM (generalized linear model), all additive materials affect the detection rate significantly.

On the other hand,  the pore size showed no significant difference.