Comparison of serum versus plasma collection in gas chromatography – Mass spectrometry‐based metabolomics

Abstract

Bovine serum, EDTA-plasma and EDTA-plasma fortified with acetylsalicylic acid (ASA) as antioxidant were compared with regard to their suitability for metabolomic studies. Metabolic fingerprints were generated from GC-TOF-MS data using the Leco ChromaTOF software in combination with the in-house retention time correction and data alignment tool INCA. A total of 6, 9 and 21 significant features with a false discovery rate of <0.05 were identified by INCA upon comparing EDTA- versus EDTA-ASA-plasma, EDTA-plasma versus serum and EDTA-ASA-plasma versus serum, respectively. To confirm that the observed signal intensities in the GC-TOF-MS fingerprints reflected true metabolite abundances, 19 amino acids, glucose and 6 organic acids were quantified by means of GC-MS using stable-isotope-labeled internal standards. As observed with the fingerprints, only the concentrations of lactate and citrate were found to be significantly lower in EDTA-plasma and serum, respectively, whereas the concentrations of the other metabolites were similar among the three sample types investigated.

Simultaneous Determination of 6 l-Arginine Metabolites in Human and Mouse Plasma by Using Hydrophilic-Interaction Chromatography and Electrospray Tandem Mass Spectrometry

“…The differences between plasma and serum are also not likely to be attributable to nonspecific monocyte or neutrophil activation due to pyrogens in the draw tube, as every effort was taken to observe proper aseptic technique. These findings underscore the important differences between plasma and serum that can make it difficult to compare data across related metabolomics studies (15, 29, 30). …”

Preanalytical Aspects and Sample Quality Assessment in Metabolomics Studies of Human Blood

“…Selected preanalytical aspects of targeted metabolomics investigations of human blood and urine by GC-MS and LC-MS (11)(12)(13)(14)(15)(16)(17), as well as the effects of delayed storage on human cerebrospinal fluid metabolomes (18 ), have been reported. Recently, protocols for metabolic profiling of serum and plasma have been published (3,7,19 ).…”

Differences between Human Plasma and Serum Metabolite Profiles

“…In the newly emerging field of metabolomics [7]–[10], there were only a few recent studies related to this subject (e.g. comparing different biofluids [11] or comparing plasma and serum from animal blood [12]). Moreover, two studies using small samples of around 15 human participants addressed this issue with conflicting results.…”