After more than a year of testing we're done with development and ready to launch - the tankDNA test is available now.
What does this test for?
Anything Eukaryotic. (What the @#$% is a Eukaryote, and why can't this guy just speak English?) Anything that's not Bacteria or Archaea. Animals, algae, fungi, plants, and odd little micro-eukaryotes like Ciliates and Amoebae that defy simple classification. Anything and everything besides Bacteria and Archae (those are covered already by our Microbiome Test)
The reason I put it this way is to emphasize that the test isn't restricted to a particular set of parasites that we're already looking for. If your tank has some oddball parasite we've never heard of before, it'll still show up on the test as long as its a Eukaryote.
How does it work?
This test uses eDNA - environmental DNA present in aquarium water samples. The organism itself is typically not present, just eDNA (which includes dissolved DNA, cells, and tissue debris). To emphasize this point: a large fraction of the DNA in these samples comes from macroscopic animals like fish, corals, snails, and sponges that are obviously not present as whole organisms in the water sample!
We sequence the same small piece of the genome in each DNA molecule in the sample, and compare these DNA sequences with a database to identify the organism each one came from. This part of the process works just like the microbiome test, just using different molecular reagents in the lab, and comparing the results with a different DNA sequence database. In this case we're targeting the 18S ribosomal DNA which is shared by all Eukaryotes, where the microbiome test targets a region of the 16S rDNA shared by all Prokaryotes.
The logistics work just like the Microbiome test. We ship you a kit, you sample the DNA, then ship it back in the prepaid shipping envelope. We analyze tankDNA samples alongside Microbiome samples in our monthly tests, so results are available 2-4 weeks after you send in your sample (depending how close to the deadline it arrived).
What kind of information do you get from the test?
I've attached a few screenshots from a recent test on one of my tanks. This is my zoa frag system so there are no interesting parasites to show you. Knock on wood, may it stay that way. But the report still lists what its looking for.
For most users the punchline comes in this section, which highlights parasites responsible for a variety of diseases in aquarium livestock.
The report also highlights a few animal pests. I must caution you that these appear to not contribute very much eDNA to the sample so that the test ends up not being very sensitive for these. If we detect Aiptasia, you've got a bunch of Aiptasia. But I imagine nobody needed a DNA test to find Aiptasia in the first place so I dont lose a lot of sleep worrying about it.
The report also includes a summary of the different sources contributing DNA to the sample. I find this useful to evaluate whether the test sampled the eukaryotic community effectively, so that we can have some confidence in a negative result. Its good to see a report with lots of diversity overall, and especially in the micro-eukaryotes like the ciliates (Intramacronucleata). My report shown here matches this description.
[In contrast, what I don't want to see (and have worked hard to minimize in our new improved tankDNA sampling kit) is a sample dominated one by one or a few groups, with only a few types and low overall diversity. In those cases DNA from one source is dominating the sample and could be obscuring the presence of rarer types. ]
Finally the complete table. Some of the most interesting stuff shows up here. In the final section we just show you all the data, classified by family, and let you sort it out. This is where you can find unexpected results.
Its always good to explore the Ciliate community, since there are several of these associated with disease. For aquarists who attribute RTN / STN in corals to the action of ciliates, this will be an especially interesting (and perhaps worrying) area to explore.
Aquarists facing diatom or dinoflagellate problems may be interested in the detailed descriptions of Diatoms and Dinoflagellates. I'll note that this tank did not have a major dino problem at the time of sampling but it sure did break it out dinos afterwards. While I find Ostreopsis commonly at low levels without problems, I've learned to pay attention when it reaches the levels I found in this sample.
Its worth exploring the rest just for fun, to get a sense for how sensitive the test is. Plant pollen, human skin fungus, all kinds of odd things show up.
Why does it matter?
A subset of tanks I've tested harbor parasites, even though they didnt have any visible symptoms. But what happens when you add a new, carefully sourced and painstakingly quarantined fish to this environment?
When we do lose a fish, we'd like to know if the tank is now infected with whatever killed it.
If we take actions to rid our tank of parasites, like a fallow period or peroxide treatment, it would be nice to have some confirmation that these actions succeeded.
I imagine there are lots of applications I'm not even thinking of for this test. If you have questions about parasites or any other eukaryotes in your tank, give it a try.
As always PNWMAS members are eligible for 20% discount on testing, just message me with your email address so I can add it to the coupon list.
Happy to answer any questions about this. Thanks!