Image by Freepik

Large-scale plasma proteomics studies have been limited by a fundamental trade-off between analytical depth and practical feasibility. While standard undepleted (NEAT) plasma analysis offers simplicity and high throughput, it lacks sufficient depth to detect clinically relevant low-abundance proteins. Alternative techniques introduce various limitations in sample volume requirements, costs, and reproducibility.

To address these challenges, Albrecht et al. developed PCA-N, a novel perchloric acid-based workflow with a neutralisation step that eliminates the need for protein extraction. This innovation drastically reduces sample volume requirements to just 5 µL of plasma while enabling parallelisation to 384-well plates. The streamlined protocol allows preparation of more than 10,000 samples per day at costs similar to standard NEAT plasma analysis.

The researchers from the Mann lab validated PCA-N using an Evosep One coupled to an Orbitrap Astral operated in Data Independent Acquisition mode. Peptides were separated on an Aurora Rapid 8×150 XT C18 UHPLC column using an EASY-Spray Source. The quantitative study demonstrated that PCA-N doubles proteome coverage compared to NEAT workflows (approximately 2,000 proteins per sample, with cumulative identifications exceeding 4,000 for larger cohorts), while maintaining comparable reagent costs under 1 USD per sample.

The researchers successfully applied PCA-N to analyse over 34,500 plasma samples across 311 days, validating its suitability for extreme-scale clinical studies. This establishes a new paradigm for population-level proteomics research that could significantly advance biomarker discovery by making deep plasma proteomics accessible and economically feasible for large-scale clinical applications.

Publication
bioRxiv

Authors

Vincent Albrecht, Johannes B. Müller-Reif, Vincenth Brennsteiner, & Matthias Mann;

Title

A simplified perchloric acid workflow with neutralization (PCA-N) for democratizing deep plasma proteomics at population scale