Environmental DNA Extraction

The C.L.A.M. device also employs special e-DNA disks to filter water through a variety of filtration and sequestering media either singly or staged together to provide a total and dissolved e-DNA residue.

In-situ Time Integrative Field Filtration Enhancing E-DNA Water Monitoring

An exciting new technology of environmental DNA (e-DNA) monitoring is fast becoming the technique of choice to establish and monitor aquatic populations. However advanced this novel tool is, it still is handicapped by using conventional grab sampling representing a snap shot in time of a dynamic changing environment.

A new sampling paradigm is needed which can provide a long term in-situ continuous sampling/filtration time integrative event, that will allow collecting the biodiversity of an ever changing dynamic aquatic environment. It should allow unattended continuous large volume filtration/collection while submerged or floating, drifting or being towed in the sample itself. It should just collect the total and dissolved e-DNA and leave the water behind, providing a small protected shipping cartridge for transport to the lab for analysis.

A novel field extractive unit called the CLAM (continuous low level aquatic monitoring) has been developed for trace organic aquatic sampling using SPE extraction that can also provide the same unique and time integrative sample for e-DNA analysis. This continuous filtration extraction device samples and filters the aquatic environment providing a unique large volume, time integrative event providing new dimensional depth to e-DNA collection.


The C.L.A.M. is a state-of-the-art small submersible extraction/filtration sampler using SPE (Solid Phase Extraction) media disks to sequester trace organics from water. The C.L.A.M. device also employs special e-DNA disks to filter water through a variety of filtration and sequestering media either singly or staged together to provide a total and dissolved e-DNA residue.

The C.L.A.M. uses low flow rate extraction/filtration (5-80 ml/minute), where water is drawn continuously through the extraction filter media disk. It provides a filtration event that can be hours or days long, allowing capture of e-DNA or trace pollutants from migratory, illicit, and episodic events.

The C.L.A.M. filters the water in-situ with the same technology the labs use on the bench. It provides a pre-extracted quantitative sampling event representing up to a hundred liters of water, lowering the laboratories’ detection limits or total e-DNA collected a hundred fold. A convenient onboard totalizer provides the volume extracted on a visual display. The small, dry extraction disk is all that is sent to the laboratory for solvent elution and analysis.


  • Provides high volume field time integrative extractions/filtration up to 100 liters.
  • Uses low flow rate extraction sampling (5-80 ml/minute)
  • Weighs just over one pound.
  • It is ballasted to float 2/3 submerged for subsurface sampling, or can be weighted for depth sampling up to 20 feet..
  • The C.L.A.M. SPE disk media is the same used in environmental laboratories for compliance trace organic analysis.
  • Special e-DNA filtration disks encapsulate lofted micron rated filters which are removable for e-DNA analysis by removing a retention band.
  • Total and dissolved e-DNA may be filtered and media extracted by using two disks luer locked together; one a filter disk, the other a media disk such as GAC
  • Micro pump suction draws the water through the extraction filtration media first, preventing analyte surface adsorption on tubing and pumps
  • Field extracts and filters submerged and unattended for 48 hours on one battery charge.
  • The small extraction disk is the only item to be sent to the lab for solvent elution or e-DNA analysis
  • The outer encasement is luer plug sealed before and after deployment preventing filter contamination from handling

The Capabilities and Advantages

  • The Clam provides a simple one step field solution to both collect and filter the aquatic environment.
  • The disposable e-DNA disks can be opened to remove the filters and media in the laboratory.
  • The filters are housed in a polypropylene encasement that acts as a filter holder, a shipping container and a vial when sealed allowing addition of stabilizers if necessary.
  • Allows two or three disks be staged together for total and dissolved studies for e-DNA . (see first photo)
  • Disk encasement prevents any contact with the filters or media until laboratory analysis.
  • The C.L.A.M unit automatically filters and collects the water in-situ and provides a transportable sealed disk for analysis after deployment.
  • Holding time issues are reduced as the filtrate residue can be chemically stabilized in the plugged disks.
  • Shipping costs, breakage and transport is made simple as you are not shipping water.
  • Each disks can represent a filtration event representing up to 100 liters of water over a 36 hour deployment, and can represent varied locations if towed or allowed to drift.
  • Contamination is reduced as the water is drawn into the disk first as it is upstream from the micro pump, tubing and totalizer.
  • The unit records with a onboard totalizer and display the total volume of water passed through it, this device is also available without the onboard totalizer.
  • Can provide 24 hour filtration collection surveillance seven days a week with a simple daily disk change, making it easier to track evasive species.

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