In addition to providing valuable new information about the nature and function of genes, molecular genetic techniques have many practical applications, including the production of pharmaceutical products and other chemicals, specialized bacteria, agriculturally important plants, and genetically engineered farm animals. These techniques are also used extensively in medical testing and, in a few cases, are even being used to correct human genetic defects. Hundreds of firms now specialize in developing products through genetic engineering, and many large multinational corporations have invested enormous sums of money in molecular genetics research. As discussed earlier, DNA analysis is also used in criminal investigations and for the identification of human remains.