Important
Preliminary tool, subject to ongoing development.
The OMNIeDNA sampler is a modular environmental DNA (eDNA) concentration system built around a standard 50 mm cotton swab pad secured within a threaded connection ring. By placing this simple, low-cost membrane at the point of water entry, the OMNIeDNA filter system creates a consistent, focused filtration interface that works across virtually any water sampling scenario. Yes, you can also use more traditional filter membranes (48-52 mm diameter) if you feel so inclined!
Whether deployed passively or with minimal active force, the system directs water through the cotton membrane, capturing cellular material and extracellular DNA efficiently on a substrate that is both widely available and easily processed for downstream DNA extraction. The threaded ring architecture allows users to adapt the same filtration core to a wide range of sampling containers, flow conditions, or collection methods, making affordable ecosystem-wide surveying accessible in diverse environments. The OMNIeDNA filter system is an inexpensive tool that puts the power of eDNA sampling into the hands of non-specialist users. Simple materials, limitless adaptability.
- OMNIeDNA TORRENT – A torpedo-shaped sampler designed specifically for use in streams and rivers, or to be deployed from behind recreational vessels and/or watercraft. So versatile that it can be deployed using buoys, docks, bridges, kayaks, dinghies, SUPs... heck, we'd even tie it to a unicorn floaty! Use the OMNIeDNA TORRENT MINI on a fishing pole for casting or trolling for eDNA!
- OMNIeDNA RAPID – Universal 1.0/1.5-liter plastic bottle threaded attachment (PET bottles with the standard 30 mm caps) for rapid filtering of collected water samples. Make sure you enjoy that soda first though, and give it a good cleaning before use!
- OMNIeDNA BULK – Universal 5.0/5.1-liter plastic bottle threaded attachment (PET carboys with a 50 mm cap) for large-volume filtration of collected water samples. You know, the kind of water jugs you keep in the hidden bunker for the zombie apocalypse?
- OMNIeDNA CANOPY – A rain/sleet/snow collection adapter to maximize filtration of canopy throughfall. When used in the rain with a plastic tarp (sorry, cannot 3D print that piece), the attached plastic bottle lets you know how much water you have collected. When used in sleet/snow, bring the bottle to room temperature to melt and invert to filter the collected water. We didn't want to exclude our (Ant)arctic partners!!
- OMNIeDNA Cartridges – Reusable filter membrane holders (for use with filter membranes of diameter < 52 mm) enable adjustable pre-filtration based on debris load and environment type, allow sterile batch assembly for fast field deployment, and are easy to decontaminate after use.
- OMNIeDNA Multi Rack – Facilitates the transfer of filter membranes into sample storage tubes in the laboratory or field. Steadily holds 15 mL and 5 mL conical tubes, plus two OMNIeDNA Cartridges. Drainage holes for easy bleach-decontamination and drying.
The OMNIeDNA system may look complex with a lot of pieces, but whether you're dangling it off a boat or screwing it onto a soda bottle on shore, you only ever need one of each to get rolling.
We call it The ABCs. Pick your A, pick your B, pick your C, and you are ready to sample.
That's it. Three pieces. So many configurations. Go get that eDNA. 🧬
This is the top half. It's where the water enters the system. Your choice depends on where you plan to sample:
| Adapter | Other Required Gear | Best Suited For | Filament Used | Approx. Print Time | Print Settings |
|---|---|---|---|---|---|
| TORRENT Cone | TORRENT Tail, rope | Moving aquatic environments (rivers, streams, towed behind a kayak or small boat) | 40g | 1hr 15min | Brim only |
| RAPID Adapter | 1.0/1.5L plastic bottles, Wide/Narrow Base | Great for quick, grab-and-go field sampling. Uses plastic bottles that are universally available. | 50g | 2hr 5min | Brim only |
| BULK Adapter | 5.1L plastic carboy, Wide Base | Perfect for sampling water from larger jugs, meaning more eDNA. However, larger jugs may be more difficult to source. | 55g | 2hr 15min | Brim only |
This is the bottom half. It dictates how the sampler stabilizes while water flows out.
| Base | Other Required Gear | Best Suited For | Filament Used | Approx. Print Time | Print Settings |
|---|---|---|---|---|---|
| TORRENT Tail | TORRENT Cone, rope | Moving aquatic environments (rivers, streams, towed behind a kayak or small boat) | 240g | 10hr | Outer Brim, 50% infill |
| Wide Base | BULK or RAPID Adapter, 5.1L or 1.0/1.5L plastic bottle | Dry land / bench-top filtration, with a sturdy footprint that is less likely to tip over while you work | Outer Brim | ||
| Narrow Base | BULK or RAPID Adapter, 5.1L or 1.0/1.5L plastic bottle | Compact fieldwork (coolers, backpacks, tight spaces) or uneven ground where it can instead be hung for maximum portability | 35g | 1hr 30min | Outer Brim |
| CANOPY Bulkhead | BULK or RAPID Adapter, 5.1L or 1.0/1.5L plastic bottle, durable plastic sheet (waterproof tarp, shower curtain liner, etc.), rope | Used as a through-fitting for a large plastic sheet or tarp to collect rainwater while suspended from the trees | 25g | 1hr 30min | Tight supports |
This is the middle piece... a threaded ring that literally connects your chosen (A) to your chosen (B).
| Connector | Required For | Filament Used | Approx. Print Time | Print Settings |
|---|---|---|---|---|
| Connector Ring | All builds | 20g | 40min | Outer Brim |
For fragile filter membranes (or those < 50 mm in diameter), the OMNIeDNA Cartridges are highly recommended to provide stability and reduce likelihood of filter membrane loss.
- Pre-load your sterile filter membranes before you leave. No more fumbling with delicate filter membranes in the field!
- At the field site, just pop the cartridge in, sample, pop it out, and seal it in a plastic bag.
- Putting your filter membranes into sample tubes? Use the tube rack as a stable platform to transfer membranes from cartridges to 15 or 5 mL conical sample tubes.
| Extra | Description | Filament Used | Approx. Print Time | Print Settings |
|---|---|---|---|---|
| Support Cartridge | 6 mm openings to provide support for fragile filter membranes while maximizing the contact area of filtered water | 5g | 20min | 100% infill |
| Mesh Cartridge | Fine 2.5 mm mesh for excluding large debris like leaves, sticks, and other material that may be in the water. It also provides support for fragile filter membranes, reducing the chances of them ripping during deployments | 5g | 15min | 100% infill |
| Multi Rack | Tube rack for holding samples while in the laboratory or in the field, greatly reducing the chances of knocking something over. Even holds two membrane cartridges for easy transfer directly into sample storage tubes. | 110g | 3hr 45min | Outer Brim |
Here are some theoretical builds/use cases (no, we haven't tested them all... yet):
| Use Case | System | Printed Parts | Justification |
|---|---|---|---|
| What fish are in my local river? (Mostly curious) | TORRENT | TORRENT Cone (A), TORRENT Tail (B), Connector Ring (C), Mesh Cartridge (Optional) | Moving water requires the torpedo-shaped OMNIeDNA TORRENT to guide water through the opening. Use a mesh cartridge to keep out larger debris and focus eDNA more efficiently, while minimizing tearing of the filter membrane. |
| What fish are in my local river? (I'm a fisherman) | TORRENT MINI | Attach the torpedo-shaped OMNIeDNA TORRENT MINI to a fishing pole and cast out multiple times, focusing eDNA efficiently onto smaller 25 mm membranes. Simple and fun! | |
| What birds visit my birdbath? | RAPID | RAPID Adapter (A), Narrow Base (B), Connector Ring (C) | Use a standard plastic bottle to collect birdbath water (multiple times, the more the better, but leave some for the birds!) with the OMNIeDNA RAPID. |
| Are there aquatic invasive species here? | BULK | BULK Adapter (A), Wide Base (B), Connector Ring (C), Support Cartridge (Optional) | Maximize detection of rare species and the volume of water that passes through the filter membrane by using a larger 5L bottle (multiple times, the more the better!) and the OMNIeDNA BULK. Use the support cartridge to maximize surface area while minimizing the chances of ripping the filter membrane. |
| What are the birds, the bees, and the trees? | CANOPY | RAPID Adapter (A), CANOPY Bulkhead (B), Mesh Cartridge (Optional) | Harvest rain throughfall under forested canopies using the OMNIeDNA CANOPY to easily sample plant and animal communities. Use the mesh cartridge to exclude leaves, sticks, and other debris that may be caught as well. Know how much rain you filtered by collecting it in a standard plastic bottle. |
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OMNIeDNA TORRENT: The sampler stays underwater via hydrodynamic design, but it relies on water flow to maintain negative buoyancy. Securely attach a ballast weight (dive weight, brick, anchor, or large rock) to any of the gear attachment points. When you MUST add a ballast weight:
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Too slow: Water speed < 1 knot (~0.5 m/s) — not enough flow to push it down.
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Too fast: Water speed > 7 knots (~3.5 m/s) — risk of planing or lifting out of the water.
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Too deep: Sampling near the bottom of the water column.
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OMNIeDNA BULK/RAPID: When using a plastic bottle, filtration will be much easier if you can poke a hole in the bottom! That way, when you invert the system, it will drain smoothly through the filter. Use tape to temporarily seal the hole while sampling (or simpler still, just be really quick)!
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OMNIeDNA CANOPY: While the system can theoretically use any waterproof sheet material, those that can hold up to stormy weather, rough terrain, and routine decontamination with bleach will inevitably perform best (e.g., thick PVC).
- Hanging: Pick a location that has plenty of trees and bring plenty of extra string to secure the corners as high as you can reach.
- Tensioning: Use a tensioning knot such as a prusik, taut-line hitch, or siberian hitch attached to each corner to easily adjust where water collects. Bring a bottle of water to test where it gathers.
- Collecting: Poke a hole in the top of your collection bottle to allow air to easily vent and water to enter. This also allows extra water can escape during large storms, instead of pooling up on the tarp. Size your collection bottle to the expected amount of rain (i.e., RAPID adapter for quick sampling, BULK adapter for lots of rain/large surface area tarps)
All components have been successfully printed on a Prusa MK4S using the following parameters:
- Filament: 1.75mm PETG or ABS plastic (recommended over PLA for toughness, frequent use in harsh environments). ABS components can be smoothed with an Acetone vapor bath to facilitate routine bleach decontamination.
- Infill: Gyroid, 30%+ (superior strength-to-weight ratio using less material, reducing print costs)
- Layer height: 0.20 mm
- Minimum perimeters per layer: 4
- Print temperature: 220°C – 260°C (PETG/ABS);
- Heated bed: 70 – 80°C (PETG); 90 – 110°C (ABS; enclosure and ventilation recommended)
- Brim/supports: 8-10mm brim when using ABS; supports were only needed for printing the Canopy_bulkhead
While these settings are optimized for PETG/ABS, users should conduct test prints to validate dimensional accuracy and layer adhesion with their chosen filament.
Printing with Prusa? We're also on Printables.com! Search 'OMNIeDNA' for easily slicing our sampler kits and components.
Original concept by Patrick Nichols
Postdoctoral Researcher | Biodiversity Genomics Research Group | University of Oulu
📧 patrick.nichols@oulu.fi
🔗 pknichols.com
🔗 biodiversitygenomics.org
Design by Jan Schulz
Social Designer
📧 schulz.janc@gmail.com
🔗 janchristianschulz.com
Design by Brendan Nichols
Principal Scientist, General Dynamics, Applied Physical Sciences Corp.
If you use this system in your research, please cite or acknowledge the original design.