Environmental DNA Science

Organisms Leave a Genetic Trace. We Read It.

Every organism that passes through a habitat sheds DNA into the environment — in mucus, skin cells, feces, and urine. Environmental DNA (eDNA) metabarcoding extracts, amplifies, and sequences that genetic material to identify which species were present without capturing or disturbing a single animal.

eDNA collectionWater & soil
Membrane filtration0.45 µm
PCR amplificationCOI · 16S · 12S
Illumina sequencingNext-gen

Why eDNA

Why eDNA Outperforms Visual Survey for Credit Purposes

Detects Cryptic Species

Nocturnal, fossorial, and rare species that transect surveys routinely miss leave eDNA signatures. A single water sample from a pond can detect all fish species present — including those rarely seen at the surface.

Non-Invasive

No trapping, netting, physical capture, or disturbance to habitat. Water filtration and soil core collection are benign procedures that leave sites undisturbed and require no wildlife handling permits.

Multi-Taxa Coverage

Three primer pairs (COI, 16S, 12S) in a single sample cover fish, amphibians, mammals, invertebrates, and bacteria simultaneously. A standard transect survey requires specialist teams for each taxonomic group.

Reproducible and Auditable

Sequencing outputs are numeric, reproducible, and archivable. Raw read counts and ASV assignments can be re-analyzed as reference databases improve — meaning a sample collected today gains precision as barcode libraries grow. Visual survey results are observer-dependent and degrade in reliability over time as observer identity changes. eDNA records do not.

From Sample to Species List

The eDNA Pipeline

01

Collection

Water drawn through 0.45 µm cellulose nitrate membranes; soil cored at multiple transect points. Samples preserved in RNAlater stabilization solution, cold-chained to lab within 48 hours.

02

Extraction

Membrane digestion and mechanical lysis for water samples; bead-beating for soil. DNA purified using commercial kits. Concentration verified via Qubit fluorimetry. Negative extraction controls included in every batch.

03

Amplification

PCR with three primer pairs targeting COI (invertebrates/vertebrates), 16S (mammals/amphibians), and 12S (fish/tetrapods). Each primer pair amplified in triplicate with blocking oligos to suppress highly-abundant domestic species.

04

Sequencing & Analysis

Amplicon libraries sequenced on Illumina MiSeq (2×300bp). DADA2 pipeline for denoising and ASV generation. BOLD Systems and custom PNW reference library for species identification. Taxa reported at ≥90% identity threshold.

See How eDNA Feeds the BHI Score