Radioactive Tracer Definition and Examples

What Is a Radioactive Tracer?

Radioactive tracers are used in nuclear medicine, as in this bone scan used to detect cancer.
Radioactive tracers are used in nuclear medicine, as in this bone scan used to detect cancer. PASIEKA / Getty Images

A radioactive tracer is a radioactive element or compound added to 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. doi:10.1017/S002966519900124X