A technetium-99m generator, or colloquially a technetium cow or moly cow, is a device used to extract the metastable isotope 99mTc of technetium from a decaying sample of molybdenum-99. 99Mo has a half-life of 66 hours and can be easily transported over long distances to hospitals where its decay product technetium-99m is extracted and used for a variety of nuclear medicine diagnostic procedures, where its short half-life is very useful.
Five modern technetium-99m generators
The first technetium-99m generator, unshielded, 1958. A Tc-99m pertechnetate solution is being eluted from Mo-99 molybdate bound to a chromatographic substrate
Technetium-99m (99mTc) is a metastable nuclear isomer of technetium-99, symbolized as 99mTc, that is used in tens of millions of medical diagnostic procedures annually, making it the most commonly used medical radioisotope in the world.
The first technetium-99m generator, 1958. A 99mTc pertechnetate solution is being eluted from 99Mo molybdate bound to a chromatographic substrate
A technetium injection contained in a shielded syringe
Technetium scintigraphy of a neck of a Graves' disease patient