Towards fast, routine blood sample quality evaluation by Probe Electrospray Ionization (PESI) metabolomics

Abstract

PESI-MS enables with its greatly simplified handling and fast result delivery the application field for high-throughput use in routine settings. In health care and research, pre-analytical errors often remain undetected and disrupt diagnosis, treatment, clinical studies and biomarker validations incurring high costs. This proof-of-principle study investigates the suitability of PESI-MS for robust, routine sample quality evaluation.One of the most common pre-analytical quality issues in blood sampling are prolonged transportations times from bedside to laboratory promptly changing the metabolome. Here, human blood (n=50) was processed immediately or with a time delay of 3 h. The developed sample preparation method delivers ready-to-measure extracts in <8 min. PESI-MS spectra were measured in both ionization modes in 2 min from as little as 2 µl plasma allowing 3 replicate measurements. The mass spectra contained 1200 stable features covering a broad chemical space covering major metabolic classes (e.g. fatty acids, lysolipids, lipids). The time delay of 3 h was predictable by using 18 features with AUC > 0.95 with various machine learning and was robust against loss of single features.Our results serve as first proof of principle for the unique advantages of PESI-MS in sample quality assessments. The results pave the way towards a fully automated, cost-efficient, user-friendly, robust and fast quality assessment of human blood samples from minimal sample amounts.Graphical abstract

Improved Feature Importance Computations for Tree Models: Shapley vs. Banzhaf

“…These are some of the most popular algorithms for generating decision trees and are quite often used for large depths of the trees. Using large-depth trees is particularly beneficial for datasets with many features and complex relationship between features (see e.g., [9,38] for a usage of trees of depth 100). Let us emphasize that the large depth of the tree e.g.…”

Applications of ambient ionization mass spectrometry in 2021: An annual review

“…Finally, PESI has been applied to the rapid analysis of human plasma. In a recent study by Bordag et al., a workflow was developed in which samples could be analysed in both positive and negative ionization mode within 2 min, enabling the detection of approximately 1200 unique features across a range of chemical classes 133 . The study campaigns for the potential for PESI‐MS to become a cost‐effective, automated user‐friendly technique for routine blood analysis.…”

“…In a recent study by Bordag et al., a workflow was developed in which samples could be analysed in both positive and negative ionization mode within 2 min, enabling the detection of approximately 1200 unique features across a range of chemical classes. 133 The study campaigns for the potential for PESI‐MS to become a cost‐effective, automated user‐friendly technique for routine blood analysis. In addition to the application of AIMS to tissue imaging and biological fluids, recent applications of AIMS also include the study of protein folding and solubility, 134 , 135 the quantification of extracellular neurotransmitters in brain tissue 136 and the characterization of metabolites in bacterial extracellular vesicles (EVs).…”