eDNA - Frequently Asked Questions

How does Environmental DNA work and what are the advantages of eDNA testing?
Environmental DNA (eDNA) testing is cost effective, more accurate than traditional methods, has less risk of pathogen transfer, and is less invasive to spec...
Fri, 21 Dec, 2018 at 11:37 AM
Can the presence of specific fish species be confirmed through the eFish eDNA assay?
Our current eFish eDNA assay tests for the presence of a group of 12 fish species: Sockeye salmon, Pink salmon, Chum salmon, Arctic Grayling, Cutthroat trou...
Fri, 21 Dec, 2018 at 11:39 AM
Can DNA from a species of fish that no longer lives in a watercourse, remain in the habitat for some time and bias the results?
Generally, eDNA persists in the environment for a short time. The duration is dependent on environmental conditions but is quantified, in standard condition...
Fri, 21 Dec, 2018 at 11:40 AM
What is the applicability of the method to terrestrial, or semi-aquatic species? Is a fully aquatic life stage mandatory for using the method?
Suspension of eDNA in water allows for transport (active or through osmotic diffusion) through the system (transport distances are variable and depend on ou...
Fri, 21 Dec, 2018 at 11:43 AM
How are hybridization issues addressed, for example, between rainbow and cutthroat trout, or subspecies?
eDNA detects mitochondrial DNA. Thus, only the maternal lineage would be detected and subspecies cannot be identified.
Fri, 21 Dec, 2018 at 11:44 AM
Does eDNA settle in lakes? Should samples be collected further down the water column?
Research is ongoing regarding distribution and persistence of eDNA in environments. However, at this time, there is evidence suggesting that most eDNA is fo...
Fri, 21 Dec, 2018 at 11:44 AM
What volume of water is required for eDNA analysis?
The ideal volume required is 1L of water per sample which is to be filtered through a cellulose nitrate filter (45μm pore size).  This increases detecti...
Fri, 21 Dec, 2018 at 11:46 AM
What type of containers are required for eDNA analysis?
Water samples should be collected in 1L Nalgene bottles.  If the water sample is to be filtered in the field, insert the rolled-up filter in a 2mL tube,...
Fri, 21 Dec, 2018 at 11:49 AM
Should eDNA samples be submitted on ice at <10C?
No.  It is not necessary to submit preserved filters on ice.  Samples should be filtered prior to submission to maximize the potential DNA recovery and redu...
Fri, 21 Dec, 2018 at 11:52 AM
How quickly should samples be submitted to the laboratory after filtration?
It depends on the contents of the water sample and what remains on the filter.  Filtering the water sample and preserving the filter within 24 hours of ...
Fri, 21 Dec, 2018 at 12:30 PM