A Barcode of Life

Barcodes are commonly used for the identification of items. Many standards exist but, in general, barcodes must be universal, unique, and easy to process. The standardization of barcodes grants great benefits, not only for everyday shopping: A unique identifier facilitates and simplifies the ordering and processing of goods all over the world.

Similarly, the distinct identification of organisms and their relationships is one of the major goals in the life sciences. What would be more suited than a barcode – a barcode of life?

Many genetic regions have been proposed for the use of being such a barcode. For eukaryotic species, the 18S gene is most commonly used today; a rather short fragment of ribosomal RNA that is evolving slowly and allows the reliable identification of most species. It is surrounded by highly conserved sequence regions that simplify the sequencing process. By this, the analysis of 18S RNA from the environment delivers a comprehensive overview of all present species, equivalent to scanning a barcode of all organisms.