User:Jamesaorr/sandbox
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Not to be confused with the DNA barcode involved in optical mapping of DNA.
DNA barcoding is a method of species identification and discovery using a short section of DNA from a specific gene or genes. That DNA sequence can be used to identify different species; in the same way a supermarket scanner uses the familiar black stripes of the UPC barcode to identify your purchases[1]. These "barcodes" are sometimes used in an effort to identify unknown species, parts of an organism, or simply to catalog as many taxa as possible.
Different gene regions are used to identify the different organism groups using barcoding. The most commonly used barcode region for animals and some protists is a portion of the cytochrome oxidase I (COI or COX1) gene found in mitochondrial DNA. Microorganisms are detected using different gene regions, for example 16S RNA is widely used in identification of prokaryotes. These gene regions are chosen because they have less infraspecific (within species) variation than interspecific (between species) variation, which is known as the "Barcoding Gap" [2].
Applications of DNA barcoding include: identifying plant leaves even when flowers or fruit are not available, identifying pollen collected on the bodies of pollinating animals or identifying insect larvae which may have fewer diagnostic characters than adults. When barcoding is used to identify a wide range of organisms from the same sample the term DNA metabarcoding is used[3][4], e.g. DNA metabarcoding of diatom communities in rivers and streams, which allow the estimation of the quality status[5].