Preanalytical variables for liquid chromatography-mass spectrometry (LC-MS) analysis of human blood specimens.

The use of liquid chromatography-mass spectrometry (LC-MS) for both diagnostics and research purposes is rapidly growing in clinical laboratories. As for more conventional areas of in vitro diagnostic testing, many preanalytical variables have an impact on these techniques and may hence jeopardize the quality of tests results. The leading preanalytical variables include patient preparation, the nature of the blood collection tubes and additives, interference from spurious hemolysis, sample handling and management, composition of blood tubes, contamination, as well as storage conditions. Therefore, the aim of this article is provide a narrative overview about the leading preanalytical issues which may ultimately influence LC-MS testing of human blood samples, and provide tentative indications, as for current evidence, about optimal preanalytical management of blood samples for proteomics and metabolomics studies. These general recommendations entail pre-storage centrifugation, use of appropriate tubes and additives, addition of bacteriostatic preservatives, enrichment and purification of samples, elimination of unsuitable specimens, rapid analysis or immediate storage at -70°C, and avoidance of analyzing frozen-thawed specimens.