Testing for DNA is “not as easy as it appears on CSI”, according to Andrew Wadge, the Food Standards Agency’s chief scientist.
Food-testing companies such as Intertek and Eurofins typically use two methods to find traces of other animals in a sample of meat. The first, polymer chain reaction, involves picking out trace amounts of a genetic code sequence particular to a certain species, such as horses and cattle, and “amplifying” them.
In the other — restriction fragment length polymorphisms analysis — scientists use enzymes to snip out strands of DNA and sort them by length.
The samples are then examined