Automated Proteomics Sample Preparation of Phosphatidylserine-Positive Extracellular Vesicles from Human Body Fluids

Extracellular vesicles (EVs) are ubiquitously secreted
by almost
every cell type and are present in all body fluids. Blood-derived
EVs can be used as a promising source for biomarker monitoring in
disease. EV proteomics is currently being analyzed in clinical specimens.
However, their EV proteomics preparation methods are limited in throughput
for human subjects. Here, we introduced a novel automated EV isolation
and sample preparation method using a magnetic particle processing
robot for automated 96-well processing of magnetic particles for EV
proteomics analysis that can be started with a low volume of multiple
clinical samples. The automation of EV purification reduced the coefficient
of variation of protein quantification from 3.5 to 2.2% compared with
manual purification, enabling the quantification of 1120 proteins
in 1 h of MS analysis. This automated proteomics EV sample preparation
is attractive for processing large cohort samples for biomarker development,
validation, and routine testing.