Our increasingly global food supply has increased the potential spread and harm from food-borne disease. Biotechnology methods can be applied to identifying pathogens and harmful chemical additives and locating their source. These methods are also used when the identity of the food itself is difficult to determine. Meat and fish for example are hard to identify once cuts have been prepared for consumption. Techniques like DNA barcoding, where DNA is isolated from the substance and sequenced, help investigators determine if the samples are correctly identified and if they were obtained illegally or poached.