ADAS achieves a perfect score in 2025 GCN eDNA proficiency test
ADAS has correctly identified 100% of blinded samples in the 2025 Great Crested Newt (GCN) Environmental DNA (eDNA) proficiency test – demonstrating the continued quality and reliability of our eDNA analysis service.
The annual GCN eDNA Proficiency Testing Scheme, run by FAPAS on behalf of Natural England, assesses the quality of eDNA analysis offered by different UK-based eDNA testing laboratories.
The laboratories provide their own eDNA sampling kits (so any level of sample degradation can be monitored) and receive back 10 blinded water samples. The composition of these samples is unknown to the laboratories, and they are asked to confirm the presence or absence of GCN DNA in each sample, along with any potential inhibition.
In every year since GCN eDNA proficiency testing first began in 2017, ADAS has correctly identified every test sample submitted and maintains a 100% success rate.
Of the eight laboratories who took part in 2025, only four correctly identified all samples and passed. We do not know the identity of the other laboratories taking part.
2025 Results
| Lab | Sample A (contained medium GCN) | Sample B (contained no GCN) | Sample C (contained no GCN) | Sample D (contained no GCN) | Sample E (contained no GCN) | Sample F (contained no GCN) | Sample G (contained low GCN) | Sample H (contained no GCN) | Sample I (contained no GCN and inhibited) | Sample J (contained low GCN) | % correct |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 4 (N) | 0 (N) | 0 (N) | 0 (N) | 0 (N) | 0 (N) | 2 (N) | 0 (N) | 4 (N) | 0 (N) | 80% |
| 2 | 12 (N) | 0 (N) | 0 (N) | 0 (N) | 0 (N) | 0 (N) | 7 (N) | 0 (N) | 0 (i) | 8 (N) | 100% |
| ADAS | 12 (N) | 0 (N) | 0 (N) | 0 (N) | 0 (N) | 0 (N) | 9 (N) | 0 (N) | 0 (i) | 6 (N) | 100% |
| 4 | 12 (N) | 0 (N) | 0 (N) | 0 (N) | 0 (N) | 0 (N) | 8 (N) | 0 (N) | 0 (i) | 10 (N) | 90% |
| 5 | 11 (N) | 0 (N) | 0 (N) | 0 (N) | 0 (N) | 0 (N) | 4 (N) | 0 (N) | 0 (N) | 4 (N) | 100% |
| 6 | 12 (N) | 0 (N) | 1 (N) | 0 (N) | 0 (N) | 0 (N) | 12 (N) | 0 (N) | 0 (N) | 12 (N) | 90% |
| 7 | 4 (N) | 0 (N) | 0 (N) | 0 (N) | 0 (N) | 0 (N) | 5 (N) | 0 (N) | 0 (N) | 1 (N) | 100% |
| 8 | 12 (N) | 0 (N) | 0 (N) | 1 (N) | 0 (N) | 0 (N) | 2 (N) | 0 (N) | 0 (N) | 2 (N) | 90% |
N: sample recorded as not inhibited
i: sample recorded as inhibited
Why is proficiency testing important?
Natural England will only accept eDNA results from laboratories that have taken part in their annual GCN eDNA proficiency test.
For ecologists using eDNA as a survey tool, it is important to ask your eDNA analysis provider how they performed this year to avoid issues further down the line
Why choose ADAS for high quality eDNA analysis?
ADAS Director Dr Helen Rees was involved in the peer reviewed Natural England’s[CH1] Technical Advice Note WC1067 which outlines the standards and specifications laboratories offering GCN eDNA analysis must follow. We continue to strictly adhere to this guidance.
Several of our papers investigating the use of eDNA analysis for species monitoring have since been published in peer-reviewed journals.
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