The FoodExpert-ID Array works by identifying an animal's DNA to determine whether it is actually present in the sample. If the DNA is there, then the animal tissue must have been present as well. For example, to detect goose DNA in a sample of goose foie gras, we first identify and design a DNA sequence that is specific to geese. If any DNA in our sample matches the sequence we identified, then we can conclude goose DNA was present and that our foie gras actually contains goose. If there was no match, then we would know goose was absent from the foie gras and that the product was mislabeled or that there was a case of food fraud.