What is DNA Barcoding?
DNA barcoding is a technique for characterizing species of organisms using a short DNA sequence from a standard and agreed-upon position in the genome. DNA barcode sequences are very short relative to the entire genome and they can be obtained reasonably quick and cheap. The cytochrome c oxidase subunit 1 mitochondrial region (CO1) is emerging as the standard barcode region for higher animals. It is 648 nucleotide base pairs long in most groups, a very short sequence relative to 3 billion base pairs in the human genome, for example. The ‘barcode’ metaphor is useful though not correct in fine detail. DNA barcodes vary among individuals of the same species, but only to a very minor degree. If the DNA barcode region is effective, the minor variation within species will be much smaller than the differences among species.
In 2003, researchers at the University of Guelph in Ontario, Canada, proposed “DNA barcoding” as a way to identify species. Barcoding uses a very short genetic sequence from a standard part of the genome the way a supermarket scanner distinguishes products using the black stripes of the Universal Product Code. Two items may look very similar to the untrained eye, but in both cases the barcodes are distinct. Until now, biological specimens were identified using morphological features. In some cases a trained technician could make routine identifications using morphological “keys”, but in most cases an experienced professional taxonomist is needed. If a specimen is damaged or is in an immature stage of development, even specialists may be unable to make identifications. Barcoding solves these problems, because non-specialists can obtain barcodes from tiny amounts of tissue. This is not to say that traditional taxonomy has become less important, but rather that DNA barcoding can serve a d
In 2003, researchers at the University of Guelph in Ontario, Canada, proposed DNA barcoding as a way to identify species. Barcoding uses a very short genetic sequence from a standard part of the genome the way a supermarket scanner distinguishes products using the black stripes of the Universal Product Code. Two items may look very similar to the untrained eye, but in both cases the barcodes are distinct. Until now, biological specimens were identified using morphological features. In some cases a trained technician could make routine identifications using morphological keys, but in most cases an experienced professional taxonomist is needed. If a specimen is damaged or is in an immature stage of development, even specialists may be unable to make identifications. Barcoding solves these problems, because non-specialists can obtain barcodes from tiny amounts of tissue. This is not to say that traditional taxonomy has become less important, but rather that DNA barcoding can serve a dual
