About eDNA Mainstream

One of the most exciting new developments in the area of disease and parasite detection is in the use of eDNA – the finding of DNA of interest in the aquatic environment.

We all have DNA, and it is something that has a pattern that is unique to each individual, whether it is ourselves, or a parasite or bacterium which potentially can cause disease. However, the challenge lies in isolating and identifying DNA from an organism of interest. Imagine if you could collect a sample of water that your fish live in and could find the DNA of some of the troublesome parasites that affect your fish.  The good news now is that science has advanced to the stage where this is now possible for a selected range of parasites.

When any living organism, whether it is a fish or a parasite moves through its environment, it sheds bits of itself which can remain in the water for a couple of weeks or more. When a sample of the water is taken for analysis, it is put through a special filter when it is collected from the pond or tank and this filter is sent to the state-of-the-art specialist robotic laboratory.

There it undergoes some unique preparation which copies small segments of genetic material. Using this technique the scientists can quickly generate substantial copies from a very small amount of DNA.

The next stage is to determine the order of the sub-structures of the DNA, and the patterns of these are unique to every living organism. This is the key to confirming which organism is present in the water which has been sampled, which translates into confirming which specific parasite or disease-causing agent is present.

It is clear that taking water samples is a much easier process than examining individual fish for the presence of specific parasites, especially if large numbers of fish may be involved and the screening process may involve post-mortem examinations of the fish in question. Practically it will take a few days for the laboratory to carry out the procedure, but the confidence level of the accuracy of the procedure is at least as good as human operators examining the fish, and in some cases may even be more accurate.

However, as with any new technique, it is sensible to use the results as a likely indication of the presence of the target parasite. No technique is 100% infallible.

Mainstream Fisheries Ltd in collaboration with Fish Treatment Ltd have been involved in the development of unique eDNA testing both in the Coarse Fish Industry and in Ornamental fish and have acquired exclusive access to a state-of-the-art specialist Robotic laboratory.