(the above is a BBC.com link, so you’ll need a non-UK IP to visit the site)

as long as there’s DNA to extract, no amount of cutting and dying can pass tilapia off as salmon. He extracts a sample of DNA, copies the gene they’re looking for and sequences it. They then compare the sequence they have with a database of animals and plants. If it matches something in the database, they’ve got an answer. So if a fillet says it’s salmon, Birck can compare that DNA with the salmon barcode. “This is really cut and dried,” he says, “it matches or it does not, end of story.”

I would imagine this technique will be useful for certifying ‘natural’ meats vs lab-grown alternatives - analagous to the certificates given today to Organic foods