LC-MS/MS analysis of steroids in the clinical laboratory. 
Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a powerful tool that is changing the way we analyse steroids in the clinical laboratory.  It is already opening up the field of steroid analysis in endocrinology and is providing new applications for individual steroids and panels of steroids in different clinical conditions.  LC-MS/MS is now well-accepted technology and is increasingly being used to replace problematic immunoassay methods because of greater sensitivity and specificity.  Improved sample preparation, modern chromatography methods, and sensitive, faster scanning mass spectrometers have all played a role in improving LC-MS/MS.  LC-MS/MS is also playing a key role in improving the quality of assays through the development of reference measurement procedures, characterisation of reference materials and multi-site calibration programmes.  There is increasing interest in multiplexing steroid assays into panels of diagnostic tests to aid and improve the diagnosis and monitoring of disease.