Targeted metabolomics identifies reliable and stable metabolites in human serum and plasma samples.
Author(s): Breier M, Wahl S, Prehn C, Fugmann M, Ferrari U, Weise M, Banning F, Seissler J, Grallert H, Adamski J, Lechner A
Publication: PLoS One, 2014, Vol. 9, Page e89728
PubMed ID: 24586991 PubMed Review Paper? No
Purpose of Paper
Conclusion of Paper
Studies
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Study Purpose
The purpose of this study was to compare the stability of 188 plasma and 159 serum metabolites during storage and to investigate the effects of freeze-thaw cycling and collection tube type on levels of 159 metabolites in serum. Plasma and serum were obtained from 20 healthy fasting patients on three different days. Plasma was collected into K+EDTA monovettes and stored for 0 min, 3 h, 6 h or 24 h at 4 degrees C, or 24 h at room temperature, before centrifugation. Serum was collected into monovettes with clot activator and centrifuged after 30 min or in monovettes with a gel separator and a clot activator and centrifuged after 30 min, 3 h, 6 h, or 24 h at 4 degrees C. Both plasma and serum were aliquoted and stored at -80 degrees C until analysis.
Summary of Findings:
The median within-person coefficients of variance (WCV) were similar for serum and plasma, but the between person CVs (BCV) and interclass coefficient correlations (ICC) were slightly higher in serum specimens than plasma specimens. While 101 metabolite concentrations were significantly higher in serum than plasma, only levels of sarcosine were significantly lower in serum than plasma. Storage of plasma for up to 24 h at 4 degrees C significantly affected the levels of 14 metabolites (p<0.01) with 5 showing significant changes after as little as 3 h at 4 degrees C. 44 metabolites were affected by storage of plasma at room temperature for 24 h, of which, 33 had increased levels compared to 0 h (p<0.05). All of the metabolites affected by storage of plasma at 4 degrees C were also significantly affected by storage of plasma at room temperature. Generally, the compound class of amino acids was the least stable during plasma storage, and the sphingolipids were the most stable, with no changes found, even after 24 h at room temperature. 19 metabolites were affected by storage of serum at 4 degrees C for up to 24 h. When blood was collected into tubes containing a gel barrier, methionine sulfoxide levels were higher than when serum was collected in tubes containing clot activator only, but no other metabolites were significantly affected by the presence of gel-barrier. Similarly, only methionine sulfoxide was affected by a single serum freeze-thaw cycle, and only 11 of the 159 metabolites tested in serum were affected by 2 freeze-thaw cycles. The authors report that neither gender nor last meal before fasting had effects on metabolite concentrations, but data was not shown.
Biospecimens
Preservative Types
- Frozen
Diagnoses:
- Normal
Platform:
Analyte Technology Platform Peptide LC-ESI-MS/MS Small molecule LC-ESI-MS/MS Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Preaquisition Patient gender Female
Male
Storage Storage duration 0 min
30 min
3 h
6 h
24 h
Storage Storage temperature 4 degrees C
Room temperature
Storage Freeze/thaw cycling 0 cycles
1 cycle
2 cycles
Biospecimen Aliquots and Components Blood and blood products Plasma
Serum
Whole blood
Biospecimen Acquisition Type of collection container/solution Serum clot activator
Serum gel-barrier with clot activator
Preaquisition Patient diet Unspecified last meal before fast
Biospecimen Aliquots and Components Centrifugation Centrifugation delays investigated