Toward Minimally Invasive Metabolomics: GC-MS metabolic fingerprints of Dried Blood Microsamples in comparison to Plasma

Abstract

Global untargeted profiles of dried blood microsamples (BμS) were studied in comparison to conventional plasma and blood samples using Gas Chromatography-Mass Spectrometry (GC-MS). Venous blood from 10 healthy, overnight-fasted individuals was collected and used to produce dried microsamples on Whatman cards, Capitainer and Mitra devices. In parallel paired plasma samples were collected. The metabolite extraction protocol was optimized and methanol was selected as the extraction solvent, while methoximation and trimethylsilylation derivatization was applied. BµS, mainly from Mitra and Capitainer devices, provided equivalent or greater information than plasma, considering the number and intensity of features, precision, and annotated metabolites intensity. Furthermore, blood microsample metabolic profiles collected from the fingertip of three individuals were compared against paired plasma and blood. Overall, the results suggest that BμS is a viable alternative for untargeted blood metabolomics, providing comparable information. Capillary blood collected using Mitra devices exhibits variations when compared to venous whole blood and plasma, with distinct trends observed across several metabolites. Consequently, further research is necessary to determine the applicability of this approach in specific contexts.