How do I take my sample?

All samples must be taken in accordance with the Natural England Technical Advice Note however, for ease we have replicated the sampling method and included it within the eDNA Protocol sent out within every kit.

When can samples be taken?

According to the technical advice note samples taken between the 15th April to the 30th June can be used for GCN eDNA analysis. Please note that we have had confirmation from Natural England that they would be willing to consider eDNA results from samples taken outside of this period so long as there is documented evidence that the GCN are still active.

Similarly, Natural England would expect consultants and others to advise against eDNA surveys when GCN are no longer active in ponds, even if it is before 30th June.

What is the turnaround time?

  • Super fast-track: 2 working days
  • Fast track: 3-5 working days (we averaged 2.6 days in 2019)
  • Standard analysis: 7-10 working days (we averaged 5.7 days in 2019)
  • Non-priority: up to 1 month (this option is for clients who do not require their results quickly)

Why should sediment be avoided?

There are three reasons as to why sediment should be avoided:

  • It is possible for DNA to persist within the sediment for longer than it would if it was floating in the water which could lead to a false-positive result i.e. in this case GCN not recently present but present a long time ago
  • In some cases, sediment can cause inhibition of the PCR analysis used to detect GCN eDNA within samples which could lead to an indeterminate result.
  • In some cases, sediment can interfere with the DNA extraction procedure which in turn can lead to an indeterminate result.

Sediment scoring

Upon sample receipt, we score your samples according to quality: good, low sediment, medium sediment, high sediment, white precipitate, and presence of algae. Please see the following link for examples. Please try to avoid sediment.

The good, the bad, and the ugly: Sediment scoring

Does it matter if algae is present in the sample?

Algae can make the DNA extraction more difficult to perform so if it can be avoided then this is helpful.

White precipitate

Sometimes samples contain a white precipitate which we have found makes the recovery of eDNA very difficult. This precipitate can be present in such high amounts that it interferes with the eDNA extraction process meaning that we cannot recover the degradation control (nor most likely the eDNA itself) at sufficient levels for the control to be within the acceptable limits for the assay, therefore we have to classify these type of samples as indeterminate.

We have started investigating the water chemistry of some of these water bodies in an effort to identify what types of pond may cause this problem and thus whether they should be avoided or not.

How long can kits be kept?

The technical advice note states that kits should be used within about two weeks of receipt, however, Natural England has agreed that from 2018 onwards kits will have a shelf life of three months.

How many kits do I need?

You will need 1 kit per pond (for up to 1 hectare in size).

In terms of larger ponds/lakes the only guidelines we have for GCN analysis using eDNA is that we can use a single kit for an area of up 1 hectare, if a lake is larger than this then you need to use multiple kits i.e. 1 kit per hectare.

We have carried out analysis on 2 lakes where 2 kits had to be used and we advised our client to use one kit to sample one half of the circumference of the lake and the second for the other half of the circumference, when they got back to the lab we analysed each kit separately.

In doing it this way if there were GCN present in a small area then any eDNA present will then not be diluted as much as it would should the whole lake be sampled into each kit.

What does the analysis involve?

All samples are processed as follows (Natural England Technical Advice Note):

  • The DNA is extracted and stored prior to PCR at -20°C
  • All samples are tested for inhibition using a real-time PCR assay, if inhibition is found then the sample is diluted 1 in 2 for subsequent analysis
  • All samples are tested for degradation using a real-time PCR assay.
  • All samples are tested for presence of GCN DNA again using a real-time PCR assay.

Even is a sample is found to be degraded it is still analysed for GCN DNA as in our experience these types of sample are found to be positive for GCN DNA around 15% of the time (2019 figures).

What do my results mean?

For an example, please see eDNA results letter example document.

positive result means that great crested newts are present in the water or have been present in the water in the recent past (eDNA degrades over around 7-21 days).

negative result means that DNA from the great crested newt has not been detected in your sample.

On rare occasions an inconclusive result will be issued. This occurs where the DNA from the great crested newt has not been detected but the controls have indicated that the sample has been degraded or the PCR inhibited in some way. This may be due to undefined components in the water chemistry or may be due to the presence of high levels of sediment or algae in your sample. A re-test could be performed but a fresh sample would need to be obtained. If water chemistry was the cause of the indeterminate then a re-test would most likely also return an inconclusive result. We have successfully performed re-tests on samples which have had high sediment content on the first collection and low sediment content (through improved sample collection) on the re-test.

Sediment content of each sample is visually recorded and reported on the results document.

Inhibition results will be noted in the appendix to the results document.

Degradation results will be noted in the appendix to the results document. If the result is recorded as evidence of decay (meaning that the degradation control was outside of accepted limits) or evidence of residual inhibition (meaning that the PCR reaction was inhibited) any negative result will be recorded as indeterminate.

What do I get for my money?

  • Kit only – £30 (available on request)
  • 2 day turnaround – £300
  • 3-5 day turnaround – £240
  • 7-10 day turnaround – £165
  • Non-priority – £140
  • Return courier charges – £20 (up to 25 kits per box, no charge for outward delivery)
  • eDNA price list 2021

These are the prices for the kit itself (everything required to collect the water sample), the analysis, and the return of the results. Additional one-way return couriering can be purchase at the cost of £20 per additional courier trip e.g. if you wanted to return samples as different times.

All prices are ex-VAT. We can also provide the kit alone upon request.

How long can water samples be kept?

According to the NE technical advice note once collected we can store the samples for up to 1 month prior to analysis. We keep these samples at 4°C (in the fridge) prior to DNA extraction and analysis and recommend that if possible samples are stored in a fridge prior to their being returned to our laboratories. Samples will be fine if they are stored at ambient temperature for a few days e.g. during the transport process.

Do you perform out of season testing?

We will perform testing outside of the survey window (15th April to 30th June) on the understanding that the results will not be acceptable to Natural England. If a negative result is obtained, a further eDNA analysis (or full traditional survey if you choose to do so) will need to be performed during the survey window. A positive result at this time will allow for accurate forward planning for the next survey season in terms of budget, project risk, and time to completion.

We have been able to detect GCN all year round in a couple of ponds with known good populations, this suggests that the larval stage is also detectible using the eDNA analysis (Rees et al, 2017). A study undertaken at the Durrell Institute of Conservation and Ecology also agrees with this finding (Buxton et al, 2017)

I have kits left over what should I do with them?

Unfortunately if you have ordered more kits than you require we will be unable to refund these unless the order is amended prior to the kits being sent out to you (in this case please email eDNA@adas.co.uk for advice and see our refund policy within our eDNA Terms and Conditions document).

Please note that we do have a kit only ordering option where analysis can be arranged once your samples have been collected. If you wish to return the unused kits to us for disposal or redistribution to charitable organisations then please return them to our laboratories alongside your pond samples.

Are you able to detect multiple species?

Please contact us if you are interested in a mass sequencing approach to detect multiple species within water bodies at the same time, we will be offering this service from autumn 2018.

We also  offer bat speciation testing from guano samples, this test can also be used for various other species including otter, mink, water vole etc.

Can I cancel/adjust my order?

Orders can be adjusted or cancelled prior to dispatch of kits (please contact eDNA@adas.co.uk), once kits have been dispatched to you your order will be subject to our tiered refunding policy (eDNA Terms and Conditions).

How do I return my samples to you?

Sample return instructions should have been sent to you as a separate email at the time of order confirmation. Please see DHL return courier instructions. Please try and book in collection of your parcel by 15.00 the day before you wish collection to be made.

Where is my VAT receipt?

For credit card orders a VAT receipt should have been sent to you at the time of ordering if you wish another copy to be sent please email us at eDNA@adas.co.uk and this will be re-issued to you.

My kits have not arrived yet?

Our courier aims to deliver before 12.00, please let us know if you do not receive your kits on your requested date as we can track the parcels progress. On rare occasions kits have not been delivered due to e.g. the supply of incorrect address details and no one being present to accept delivery.