To conduct DNA testing of fish, the Boston Globe hired the Biodiversity Institute at the University of Guelph, which houses the International Barcode of Life. This 26-nation consortium uses a novel method of genetic analysis to quickly and inexpensively identify species. The method compares a snippet of a specimen’s DNA against an existing DNA library to identify the species. Scientists use a fragment of a gene found in a cell’s mitochondria that is short enough to be quickly sequenced, but long enough to vary significantly from one species to another. The technique is called DNA barcoding because, just as a supermarket scanner reads a barcode to distinguish a can of beans from a carton of milk, the DNA snippet separates one species from another.