Environmental DNA (eDNA)
Definition
DNA extracted from an environmental matrix (soil, water, air filter) rather than from a discrete specimen. For plant forensics, eDNA metabarcoding generates the species composition of a plant community from bulk soil, potentially linking a location to trace soil on a suspect.
- Source
- Bulk environmental matrix (soil, water, air filter)
- Method
- Metabarcoding of a plant community
- Forensic use
- Links a location to trace soil found on a suspect
Common questions
How does eDNA metabarcoding differ from targeted single-species plant DNA analysis?+
Metabarcoding sequences all plant DNA present in a bulk sample and identifies the mixed species composition at once, rather than testing for one known target species, which suits soil trace evidence where the plant sources are unknown in advance.
What limits the use of eDNA evidence to place a suspect at a scene?+
The species profile can indicate a habitat type or region rather than a single unique location, since similar plant communities can occur at multiple sites, so eDNA typically corroborates other trace or geographic evidence rather than standing alone.
Related terms
- Metabarcoding
- Sequencing a mixture of DNA from many organisms simultaneously and using bioinformatics to assign each read to a taxon. For plant eDNA,...
- Microsatellite (SSR) Profiling
- Detection of variation at short tandem repeat loci in the nuclear genome. SSR loci are codominant, highly polymorphic, and reproducible across labs....
- Next-Generation Sequencing (NGS)
- High-throughput sequencing technologies (Illumina, Ion Torrent, Oxford Nanopore) that produce millions of reads in parallel. For plant forensics, they enable whole-chloroplast genome...
- Validation (Forensic Method)
- The process of demonstrating that a method is fit for its intended forensic purpose: reproducibility, sensitivity, specificity, and performance on simulated casework...
- Whole-Chloroplast Phylogenomics
- Using complete chloroplast genome sequences (plastomes, ~120-160 kb) to reconstruct phylogenetic relationships and assign an unknown plant to a geographic clade or...