Summary
Identifying species using short standardised gene regions such as COI in animals.
In depth
COI (cytochrome c oxidase I) for animals, rbcL and matK for plants, ITS for fungi. The Barcode of Life Data System holds millions of records. Limitations include hybridisation and incomplete libraries.
Barcodes reveal cryptic species and help identify larvae, fragments and processed products. Reference libraries must be complete.
Key idea: a short DNA sequence can label a species.
DNA barcoding identifies species from a short standard DNA sequence. For animals, about 650 base pairs of the mitochondrial cytochrome c oxidase subunit I gene (COI) are used; plants use plastid genes (rbcL and matK), fungi use the ITS region, and bacteria 16S rRNA.
A sample sequence is compared with a reference library such as BOLD, with gaps between species often exceeding variation within species. Applications include identifying larvae and fragments, detecting food fraud (mislabelled fish), tracing illegal wildlife trade, monitoring invasive species and discovering cryptic species. Metabarcoding sequences mixed samples. Limits include incomplete libraries and hybridisation.
Example: barcoding showed that some sushi sold as red snapper was another fish.
Key idea: a barcode is a tag, not a full classification.
Frequently asked questions
What is DNA Barcoding?
Identifying species using short standardised gene regions such as COI in animals.
Which area of biology covers DNA Barcoding, and how advanced is it?
DNA Barcoding is one of the 52 topics in Taxonomy & Biodiversity. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Environmental DNA, Citizen Science in Biodiversity, Taxonomy.
Can you give an example of DNA Barcoding?
Barcoding exposed mislabelled fish in markets.
What should I learn before DNA Barcoding?
Work through the Beginner topics in Taxonomy & Biodiversity first, such as Taxonomy, Binomial Nomenclature, Taxonomic Hierarchy, then return to DNA Barcoding. Intermediate topics assume the Beginner vocabulary.
What topics are related to DNA Barcoding?
The closest topics to DNA Barcoding are Environmental DNA, Citizen Science in Biodiversity, Taxonomy, Conservation Genomics. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand DNA Barcoding?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for DNA Barcoding. To practise the whole of Taxonomy & Biodiversity, use the Taxonomy & Biodiversity quiz.
How is DNA Barcoding different from Environmental DNA?
DNA Barcoding: Identifying species using short standardised gene regions such as COI in animals. Environmental DNA: DNA shed by organisms into water or soil allows detection of species without capturing them. Read both side by side and note what each one explains.
How should I study DNA Barcoding step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Environmental DNA and explain the difference aloud. Finally, take the Taxonomy & Biodiversity quiz and come back to this page for any question you miss.