DATE: October, 24, 2017
TIME: 7:00 AM PDT
Metabolomics focuses on the chemical processes central to cellular metabolism. A robust mass spectrometry solution for screening metabolites is of increased interest allowing for a more integrated and routine analysis. A new QTOF System was developed for routine, robust workflows which require minimal MS expertise. The system integrates all data acquisition, processing and review in a single software. A prostate cancer study was used to determine whether the untargeted metabolomics workflow using the X500R System could find key differences between the samples.
Urine samples were obtained with disease classifications, previously determined using accepted clinical techniques. Samples were extracted, dried and reconstituted in 50 µL of 0.1% formic acid in water. A standard reverse phase gradient was used employing mobile phase A as 0.1% formic acid in water and mobile phase B as acetonitrile. The data were collected using information dependent acquisition (IDA) on the X500R QTOF System (SCIEX). Data were processed in MarkerView™ Software 1.3 and PCA analysis was performed. Ions of interest were saved as an Interest List and copied into SCIEX OS Software where a formula was generated for each mz - RT ion pairs, these formulae were scored using MS and MS/MS data, and searched using databases.
In this study, samples from a pilot prostate cancer study were analyzed and a clear difference between healthy and disease urine samples was detected using this untargeted metabolomics approach, confirming the original disease classifications. MarkerView Software was used to determine a list of the statistically significant analytes that distinguished the samples, and then the SCIEX OS compound searching provided formulae finding as well as structural matching through ChemSpider database. Most changes were in the small molecule amino acids. This pilot study provided confidence in the approach, and the next larger phase of the study analyzing a much larger set of samples is underway.