The following services are offered by the NERC Metabolomics Facility.
A. Advice
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Before you apply to use the facility, we will discuss with you how best to design your metabolomics experiment. Please see "How to apply for services".
B. Sample Extraction
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Extraction of metabolites from biological matrices.
This will be routinely carried out by visiting scientists after training provided by us. Each sample will be extracted to provide a polar and non-polar fraction, based on the method by Bligh and Dyer.
C. Mass Spectrometry
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We currently offer direct infusion MS, using our "SIM-stitching" method, of polar and non-polar metabolites in positive and negative ion modes on a Thermo LTQ FT Ultra mass spectrometer.
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Specific metabolites can be characterized with high mass accuracy (using internal standards) and MSn fragmentation.
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We are planning to develop LC-MS methods for the more detailed analysis of lipids and polar metabolites.
D. Nuclear Magnetic Resonance Spectroscopy
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We currently offer 1-D and 2-D J-resolved NMR spectroscopy of polar metabolites on a Bruker Avance DRX-500 spectrometer.
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Metabolite identification and quantification from 1-D NMR spectra can be conducted using the Chenomx NMR Suite. It is preferable that visitors conduct their own analyses in Birmingham, after training by NBAF-B staff. In instances where confirmation of identification of a few metabolites is crucial, biological samples can be spiked with pure metabolites and NMR spectra re-recorded.
E. Data Analysis
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Raw spectral data will be processed using custom-written software (in Matlab). Subsequent data analysis will comprise of univariate and/or multivariate methods, e.g. principal components analysis (PCA), partial least squares regression (PLS-R), or PLS discriminant analysis (PLS-DA).
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Format of NMR data: matrix containing samples (rows) x NMR bins (columns).
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Format of MS data: matrix containing samples (rows) x MS peaks (columns).
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Format of output from univariate analyses: individual NMR bins/buckets or MS peaks and their associated p values, ranked according to significance.
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Format of output from multivariate analyses: scores and loadings plots, as well as the top loadings that contribute to any separation between sample groups.
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Currently, LC-MS data will solely be interpreted using Xcalibur software and comparison with known standards.
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It is preferable that visitors conduct their own statistical analyses in Birmingham, after training by NBAF-B staff.