text: Tc is a very versatile radioisotope, and is the most commonly used radioisotope tracer in medicine. It is easy to produce in a technetium-99m generator, by decay of Mo.
  :Mo → Tc +  + 
  The molybdenum isotope has a half-life of approximately 66 hours (2.75 days), so the generator has a useful life of about two weeks. Most commercial Tc generators use column chromatography, in which Mo in the form of molybdate, MoO is adsorbed onto acid alumina (AlO). When the Mo decays it forms pertechnetate TcO, which because of its single charge is less tightly bound to the alumina. Pulling normal saline solution through the column of immobilized Mo elutes the soluble Tc, resulting in a saline solution containing the Tc as the dissolved sodium salt of the pertechnetate. The pertechnetate is treated with a reducing agent such as Sn and a ligand. Different ligands form coordination complexes which give the technetium enhanced affinity for particular sites in the human body.
  Tc decays by gamma emission, with a half-life: 6.01 hours. The short half-life ensures that the body-concentration of the radioisotope falls effectively to zero in a few days.