[The importance of methodology in serum testosterone measurement: comparison between a direct immunoassay and a method based on high performance liquid chromatography and tandem mass spectrometry (HPLC/MS-MS)].

Serum testosterone in its total or free form, is a highly valuable diagnostic test and is available in the great majority of clinical laboratories. This reality was possible due to the development of simple and direct assays, adaptable to large automatic systems. Recent publications have called attention to the limitations of these simplified methodologies, mainly in samples with low concentration, as women and children.