Collection and Preparation of Clinical Samples for Metabolomics.

A wide range of biofluids (urine, serum, plasma, saliva, etc.) as well as cellular and tissue samples can be collected and investigated in clinical metabolomic studies. The choice of sample is dependent on the clinical question being investigated with biofluids typically studied to identify biomarkers, whereas tissues and primary/immortalised cells are typically studied to investigate mechanisms associated with pathophysiological processes. Methods applied to collect samples, quench metabolism and extract samples differ between sample types from simple collect, dilute and analyse methods for urine to complex washing, quenching and biphasic extraction methods for tissues. The range of sample collection and extraction methods are discussed with sample-specific considerations highlighted. Finally, methods for imaging of cells and tissues and for in vivo metabolomic analysis will also be introduced.