DNA Barcoding is a system to provide species identification through the use of the DNA sequence of a short and standardized gene region – the “Barcode”.
The gene region of interest for nearly all animals is a ~650 bp stretch of the mitochondrial cytochrome c oxidase 1 gene (COI).
How does it work?
DNA is extracted from the sample and COI region is amplified using PCR technology. The PCR product will be sequenced and the obtained sequence is analysed using the BOLD (Barcode of Life Data systems) and the GeneBank databases. The final result is the identified species.
What are the advantages?
Other technologies (e.g. species-specific PCR) require multiple tests and so are economically prohibitive, whereas DNA Barcoding provides identification with one test.
There are various initiatives (e.g. FISH-BOL and the Mammal Barcode of Life) that constantly enter new species in the BOLD database. Currently, more than 77,000 formally characterised species are in the database and it is expected that the number will increase significantly in the forthcoming years. The final goal is to characterize all animal species on earth with barcodes.