Indium In 111 oxyquinoline
Indium In 111 oxyquinoline (oxine) is a diagnostic radiopharmaceutical intended for radiolabeling of autologous leukocytes.  It is composed of a 3:1 saturated complex of In-111 isotope and oxyquinoline. Indium-111 decays by isomeric transition and electron capture to cadmium-111, emitting a gamma ray that can be detected with a gamma ray camera. It is therefore useful in nuclear medicine, and is used in the labeling of leukocytes for localization of processes to which leukocytes migrate, such as those associated with abscesses or other infections. The degree of accuracy may vary with labeling techniques and with the size, location and nature of the inflammatory process.  Following intravenous administration, the lipid-soluble complex is able to penetrate platelet cell membranes. Once inside, Indium detaches from the oxyquinoline complexes and becomes attached to cytoplasmic components.