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MB Sample ID: SA094615
| Local Sample ID: | HFD-VEH18 |
| Subject ID: | SU001383 |
| Subject Type: | Mammal |
| Subject Species: | Rattus norvegicus |
| Taxonomy ID: | 10116 |
| Genotype Strain: | Sprague Dawley |
| Age Or Age Range: | 240 days |
| Gender: | Male |
| Animal Animal Supplier: | Harlan |
| Animal Housing: | polycarbonate-free caging |
| Animal Light Cycle: | 14-hr light and 10-hr dark |
| Animal Feed: | Phytoestrogen Reduced II 18-5 (Ziegler Bros, Inc) or D09100301 (Research Diets, Inc) |
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Sample Preparation:
| Sampleprep ID: | SP001391 |
| Sampleprep Summary: | Metabolites were extracted from crushed liver samples and a mouse liver pool was used for quality control. Twenty-five mg of crushed liver was used for the metabolic extraction. The extraction step started with the addition of 750 µL ice-cold methanol:water (4:1) containing 20 µL spiked internal standards to each tissue sample. Ice-cold chloroform and water were added in a 3:1 ratio for a final proportion of 1:4:3:1 water:methanol:chloroform:water. The organic (methanol and chloroform) and aqueous layers were mixed, dried and resuspended with 50:50 methanol: water. The extract was deproteinized using a 3kDa molecular filter (Amicon ultracel-3K Membrane; Millipore Corporation, Billerica, MA) and the filtrate was dried under vacuum (Genevac EZ-2plus; Gardiner, Stone Ridge, NY). Prior to mass spectrometry, the dried extracts were re-suspended in identical volumes of injection solvent composed of 1:1 water: methanol and were subjected to liquid chromatography-mass spectrometry. Fifty µl of sample was used for preparation. Internal standards were spiked into the samples. Then it was processed through a 3 kDa filter. After that, 50 µl of sample was diluted with 450 µl solvent (methanol: water = 50:50 v/v) and subjected to LC/MS analysis. The injection volume was 10 µl. For internal standards, high-performance liquid chromatography (HPLC)-grade acetonitrile, methanol, and water were procured from Burdick & Jackson (Morristown, NJ). Mass spectrometry-grade formic acid was purchased from Sigma-Aldrich (St Louis, MO). Calibration solution containing multiple calibrants in a solution of acetonitrile, trifluroacetic acid, and water was purchased from Agilent Technologies (Santa Clara, CA). Metabolites and internal standards, including N-acetyl Aspartic acid-d3, Tryptophan-15N2, Sarcosine-d3, Glutamic acid-d5, Thymine-d4, Gibberellic acid, Trans-Zeatine, Jasmonic acid, 15N Anthranilic acid, and Testosterone-d3, were purchased from Sigma-Aldrich (St. Louis, MO). Three LC- MS methods were used to separate metabolites. Method A: In ESI positive mode the HPLC column was waters X-bridge amide 3.5 µm, 4.6 x 100 mm (Waters, Milford, MA). Mobile phase A and B were 0.1% formic acid in water and acetonitrile, respectively. Gradient flow: 0-3 min 85% B; 3-12 min 30% B, 12-15 min 2% B, 16 min 95%B, followed by re-equilibration till the end of the gradient 23 min to the initial starting condition of 85% B. Flow rate of the solvents used for the analysis is 0.3 ml/min. Injection volume was 10 µL. Method B: In ESI negative mode the HPLC column was waters X-bridge amide 3.5 µm, 4.6 x 100 mm (Waters, Milford, MA). Mobile phase A and B were 20 mM ammonium acetate in water with pH 9.0 and 100% acetonitrile, respectively. Gradient flow: 0-3 min 85% B, 3-12 min 30% B, 12-15 min 2% B, 15-16 min 85% B followed by re-equilibration till the end of the gradient 23 min to the initial starting condition of 85% B. Flow rate of the solvents used for analysis is 0.3 ml/min. Injection volume was 10 µL. Method C: In ESI positive mode the HPLC column was Luna 3 µM NH2 100 A0 Chromatography column (Phenomenex, Torrance, CA). Mobile phase A and B were 20 mM ammonium acetate in water with pH 9.0 and 100% acetonitrile, respectively. Gradient flow: 0-3 min 85% B, 3-12 min 30% B, 12-15 min 2% B, 15-16 min 85% B followed by re-equilibration till the end of the gradient 23 min to the initial starting condition of 85% B. Flow rate of the solvents used for analysis is 0.3 ml/min. Injection volume was 10 µL. For data acquisition through LC/MS analysis, 10 µL of suspended samples were injected and analyzed using a 6495 triple quadrupole mass spectrometer (Agilent Technologies, Santa Clara, CA) coupled to a HPLC system (Agilent Technologies, Santa Clara, CA) via Multiple reaction monitoring (MRM). Source parameters were as follows: Gas temperature- 250°C; Gas flow- 14 l/min; Nebulizer - 20psi; Sheath gas temperature - 350°C; Sheath gas flow- 12 l/min; Capillary - 3000 V positive and 3000 V negative; Nozzle voltage- 1500 V positive and 1500 V negative. Approximately 8–11 data points were acquired per detected metabolite. The data acquired using Agilent mass hunter software and data was analyzed using mass hunter quantitative analysis software. |
| Sampleprep Protocol Filename: | Targeted.MS.method.pdf unbiased.liver.MS.method.pdf |
