Return to study ST001328 main page

MB Sample ID: SA096369

Local Sample ID:GCMS_4W2
Subject ID:SU001402
Subject Type:Mammal
Subject Species:Mus musculus
Taxonomy ID:10090
Genotype Strain:C57BL/6
Age Or Age Range:8-10 weeks old
Gender:Male and female
Animal Feed:ad libitum
Animal Water:ad libitum

Select appropriate tab below to view additional metadata details:

Sample Preparation:

Sampleprep ID:SP001410
Sampleprep Summary:After lung collection, 1 mL of 50 % methanol was added to 100 mg of Mtb-infected or uninfected lung tissue and homogenized in a dounce homogenizer to prepare a uniform suspension. For CE-TOF/MS, 200 uL of homogenate were mixed with 200 L of 0.2 M formic acid and vortexed for 2 min. The samples were cleared by centrifugation at 16000 x g for 10 min at 4 °C and the supernatant was filter-sterilized using 0.22 um spin-X columns (Sigma). For GC-QTOF/MS and LC-QTOF/MS, 200 uL of each sample homogenate were mixed with 800 L of 80:20 methanol:MTBE (Methyl tert-butyl ether) and vortexed for 2 min. Metabolites were then extracted for 1 h with shaking at room temperature and then centrifuged at 4000 x g at 20 °C for 20 min. Supernatants were sterile filtered using 0.22 um Spin-X columns. All samples were passed through a Millipore filter (30-kDa cutoff) to remove large proteins. Samples were dried under high vacuum and stored at -80 °C until further platform-specific processing and analysis. For CE-ESI(+)-TOF/MS analysis, The dried samples were resuspended in Milli-Q water containing 0.1 mM formic acid and 0.2 mM methionine sulfone (internal standard) (Sigma-Aldrich, Germany) by vortexing for 1 min. After subsequent centrifugation (12600 x g, 15 min), the resulting clear solution was analyzed. For GC-QTOF/MS analysis, The above described dried samples were re-suspended in 450 µL of MeOH:H2O:MTBE (74:10:16) and after centrifugation at 12600 x g, 15 min at 4 °C, the supernatant was transferred to a vial with insert and evaporated to dryness under high vacuum. The obtained dried extracts were derivatized by a MPS autosampler for GC/MS analysis as previously described (Fiehn O., 2006). For LC-QTOF/MS analysis, The above described dried samples were resuspended in 200 µL of methanol:water:MTBE (7.4:1:1.6), vortexed for 1.5 h and centrifuged (4000 x g, 10 min, 4 °C). Clear solutions were analyzed.
Sample Derivatization:In GC-EI-QTOF/MS analyses, Briefly, aldehyde and keto groups were first converted to O-methyloximes by reaction with 10 µL pyridine containing 15 mg/mL O-methoxyamine (Sigma-Aldrich, Germany) for 60 min at 70 °C. In a second step, acid hydrogen-containing metabolites were trimethylsilylated by reaction with 10 µL N,O-Bis(trimethylsilyl)trifluoroacetamide (BSTFA) (Sigma-Aldrich, Germany) to enhance the GC/MS metabolite coverage