Our top eDNA sampling tips

When sampling for great crested newts, don’t step in the pond! You may have brought in eDNA on your wellies!

Stepping in the water can also disturb sediment which may release historical great crested newt DNA. Instead if you are struggling to access deeper water areas, rather than stepping in the water attach your 30ml dipper to a long pole; we’ve found a nearby stick or a garden cane with a couple of zip ties, makes a great extension.

When collecting water, although its best to sample open water and areas of vegetation, it’s best to avoid areas of very densely packed mats of vegetation; evidence suggests that DNA is less likely to be detected in water taken from these areas – either because of a lack of newt activity, the difficulty of sample collection in these areas or both!

Swapping kits is a no no! Each lab will have their own degradation controls that only they know and can search for. Freezing a sample is a bad idea! Ok it may slow down the degredation DNA in your sample, but it risks damaging the storage tubes, so the test can’t be performed!

eDNA is quite persistent, it is often best to sample for eDNA before you do any other great crested newt sampling. Virkon, is commonly used in the field to stop the spread of infections between sites and clean bottle traps between seasons however it’s not the best for destroying eDNA and preventing contamination between ponds. Virkon has also been shown to negatively impact the early life stages of amphibians! A 10% bleach solution will be much more effective in destroying eDNA. Reusing bottle traps from previous years also adds a contamination risk so make sure you properly clean them between trapping.

A hot car is bad for your kits, before and after particularly after samples are collected. High temperatures can cause DNA to degrade faster than normal, which can impair results. You could try a cool box in the car to keep them chilled – but just remember – no freezing your kits, as this can cause the tubes to crack and leak before they get to the lab!