ADAS scores 100% in Great Crested Newt eDNA proficiency testing for seventh year in a row!
In 2023, ADAS has again correctly identified 100% of blinded eDNA samples in the FAPAS great crested newt eDNA proficiency test. Of the seven service providers taking part this year, five identified all blinded samples correctly (two laboratories missed a low eDNA containing sample). Laboratory names are anonymised, so we do not know the names of other companies taking part.
The proficiency testing scheme has been carried out every year since 2017 to provide evidence of the quality of eDNA analysis offered by the different UK testing labs. It also offers underperforming labs a chance to improve their procedures.
Proficiency testing for eDNA
FAPAS, who oversee the proficiency testing scheme, prepares and sends ten different blinded samples to each participating lab for analysis. Testing laboratories provide their own eDNA sampling kits so to assess the level of sample inhibition and degradation.
ADAS correctly identified all 10 samples that included samples containing different levels of great crested newt eDNA (low and medium). In addition, we successfully identified samples that had been deliberately inhibited by FAPAS.
It is vital that labs identify inhibited and/or degraded samples. These may incorrectly score a waterbody as negative for GCN even if they are actually present. Much of the success (a positive or negative result) of an eDNA test will depend on the quality of the water sample. Whilst we do our best to resolve results recorded as indeterminate (where samples are inhibited or are extensively degraded), we won’t always be able to determine a result from a poor water sample. High amounts of organic material, sediment, etc. could contaminate a sample.
FAPAS score results as ‘satisfactory’ if both the PCR result is correct and inhibition or not) is recorded as expected.
| A | B | C | D | E | F | G | H | I | J | |
|---|---|---|---|---|---|---|---|---|---|---|
| Blank (Inhibited) | Low positive for GCN | Medium positive for GCN | Blank | Low positive for GCN | Blank | Blank | Low positive for GCN | Blank | Blank | % ADAS Score |
| Inconclusive | 1/12 | 7/12 | 0/12 | 3/12 | 0/12 | 0/12 | 1/12 | 0/12 | 0/12 | 100% |
number/12 is the number PCR replicates positive out of 12.
What do GCN eDNA results mean?
The presence/absence of an eDNA detection within pond water samples gives a reliable indication of recent GCN presence within that waterbody.
It’s always important to take a good sample to achieve a conclusive result. See our sampling guidance video for more information.
At ADAS, we offer super fast-track to non-priority services (2, 5 or 10 day turn around time). We will send results as soon as they are ready, regardless of turnaround time chosen. Visit our eDNA service page or email eDNA@adas.co.uk to learn more and to book an analysis slot. To avoid disappointment, book your analysis slot as soon as possible.