The system, which is being designed in the Chemical Sciences Division at Oak Ridge National Laboratory, takes advantage of stable isotopes, which are found throughout nature. The technique uses the abundance of natural stable isotopes of carbon, hydrogen, nitrogen, oxygen, and other light elements found in biological and chemical materials to identify their source. The abundance of these stable isotopes of both natural and manmade compounds varies depending on three factors: starting raw materials and substrates used, manufacturing and culturing processes, and geographic locations of the production sites. The research project has discovered that microbial agents cultured under controlled conditions inherit the isotopic compositions of growth media and substrates in predictable ways. Because the isotopic composition of organic substrates and media water most likely varies according to the source and manufacturing processes of raw materials and the geographic locations, even bacteria of the same strain can be readily distinguished on the basis of their isotopic compositions. This may also be the case for various batches of biological and chemical agents produced in the same laboratories if raw materials and/or processes differ. The use of stable-isotope fingerprints of multi-elements should make it possible to distinguish most, if not all, chemical and biological agents.