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MB Sample ID: SA083451
Local Sample ID: | 19-Synechocystis_6803-cell-4-1 |
Subject ID: | SU001266 |
Subject Type: | Bacteria |
Subject Species: | Synechocystis sp. PCC 6803 |
Taxonomy ID: | 1148 |
Genotype Strain: | NCBI:txid1148 |
Cell Biosource Or Supplier: | ATCC |
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Sample Preparation:
Sampleprep ID: | SP001274 |
Sampleprep Summary: | Briefly, 6 mL of 75% methanol (MeOH) was added to pellets, vortexed, and transferred to glass vials. 9 mL of 100% methyl tert-butyl ether (MTBE) was added, vortexed for 30 seconds, placed on automatic shaker for 1.5 hours at 4 ºC, and sonicated for 15 minutes. 3.75 mL of water was added, each extraction was vortexed by hand for 1 minute, and centrifuged for 10 minutes at 3,270g at 4ºC. A biphasic solution with a pellet formed: the top, green MTBE layer and the bottom, clear MeOH:H2O layer were separated into separate tubes and dried under N2,gas overnight. The pellet was stored at -80 ºC. After drying, the MTBE layer was resuspended in 100 uL 1:1 toluene:MeOH, transferred to a LC-MS vial insert, and stored at -80C for <1 month prior to MS analysis. The MeOH:H2O layer was resuspended in 1 mL of 1:1 H2O:MeOH, transferred to a 1.7 mL centrifuge tube and spun at 15,000g for 2 minutes at 4 ºC. The supernatant was split into two 465 µL aliquots—one for GCMS and one for LC(HILIC)MS—in glass vials and dried under N2,gas. The protocol outlined above is suitable for filter-quenched cyanobacteria samples and centrifuged cell pellets. The polar methanol/water fraction resulting from the biphasic extraction was processed for analysis by hydrophilic interaction liquid chromatography (HILIC) LC-MS. Dried samples were resuspended in 100 µL 1:1 H2O:MeOH and 10 µL were aliquoted into a pooled QC sample. Samples were stored at -80 ºC until analysis. The pooled QC sample was mixed and aliquoted into twelve vials. A QC injection was run every tenth injection. The dried polar fraction for analysis by GC-MS was stored at -80 ºC until derivatization, immediately prior to MS analysis. Samples were derivatized in 30 uL methoxyamine HCl and 30 uL MSTFA, as specified in the following section. Ten microliters were removed from each sample to create a pooled QC sample, mixed, and aliquoted into thirteen vials. A QC sample was run after every sixth injection. The non-polar MTBE phase was processed for non-targeted LC-MS analysis. Twenty microliters from each sample were pooled, mixed, and aliquoted into thirteen pooled QC samples. QC injections were placed after every sixth injection. |