Science, Tech, Math › Science Radioactive Tracer Definition and Examples What Is a Radioactive Tracer? Share Flipboard Email Print PASIEKA / Getty Images Science Chemistry Chemical Laws Basics Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated December 05, 2018 A radioactive tracer is a radioactive element or compound added to a material to monitor the material's distribution as it progresses through a system. The use of a radioactive tracer is called radiolabeling, which is one form of isotopic labeling. Radioactive Tracer Uses Radioactive tracers form the basis of some medical imaging systems, such as PET scans. Radiolabeling is used in research to trace the path of elements in biochemical reactions and cells. Radioisotopes are also used to track the flow of fluids, particularly in the petroleum and natural gas industry. Examples of Radioactive Tracers Usually, the isotopes chosen for use as radioactive tracers have a short half-life. Thus, they are produced via nuclear reactions. Examples of commonly used radioactive tracers include tritium, carbon-11, carbon-14, oxygen-15, fluorine-18, phosphorus-32, sulfur-35, technetium-99, iodine-123, and gallium-67. Sources Fowler, J. S.; Wolf, A. P. (1982). The synthesis of carbon-11, fluorine-18, and nitrogen-13 labeled radiotracers for biomedical applications. Nucl. Sci. Ser. Natl Acad. Sci. Natl Res. Council Monogr. 1982.Rennie, M. (1999). "An introduction to the use of tracers in nutrition and metabolism." Proc Nutr Soc. 58 (4): 935–44.