ACMan is developing both targeted and discovery workflows for metabolomics, initially in plasma and urine. Other sample types will be possible in the future.
These analyses involve the use of High Pressure liquid chromatography and quadrupole time of flight mass spectrometry (UHPLC-QTOF) and Agilent Mass Profiler Professional (MPP) chemometric analyses software. Samples are analyzed in a focused approach using reverse phase (RP) chromatography for hydrophilic compounds and hydrophobic interaction chromatography (HILIC) for hydrophobic compounds in both positive and negative ion mass spectrometry (4 separate analyses).
Targeted workflow involves the use of analytical standards used in the newborn screening program at C&W. These standards are included with every sample set in order to accurately identify 138 compounds that are targeted to major metabolic pathways including amino acids, purine/pyrimidine, organic acids and acyl carnitines.
Discovery workflow is all remaining peaks (or entities) in the chromatogram that are not part of the targeted compounds. For plasma samples there are typically between 2,000 -3,000 entities.
The PowerPoint presentation below illustrates a pilot project designed by Dr. Graham Sinclair to identify preanalytical variables (freeze-thaw, delayed processing, postprandial vs fasting blood collection) that could potentially affect results in all studies.