Quantitative assessment of a novel device designed for patient-centric sampling of dried plasma using targeted proteomics

The advancements in technology have significantly enhanced proteomics by improving the quality, depth, and timeliness of proteomic data, making mass spectrometry a promising tool for personalized medicine. To enable successful longitudinal population-level monitoring, it is essential to have cost-efficient and convenient sample collection methods that yield reliable results. Microsampling performed by patients in their own homes fulfills this requirement. In this study, we evaluate a novel microsampling device that readily prepares a dried plasma sample from blood collected through a finger prick. The device was assessed quantitatively through a targeted proteomics approach, using a selection of stable isotope-labeled protein fragments as standards for plasma proteins spanning a range from 1,300 µM to 30 nM. All samples were analyzed using selected reaction monitoring to ensure quantitative robustness. The device was assessed both from a storage perspective and across a group of healthy donors to ensure reliable performance between individuals. The dried plasma obtained from the device shows an excellent quantitative correlation with conventional plasma (R > 0.99) and high quantitative precision, with a coefficient of variance (CV) below 10% for 80% of all peptides quantified in the group of healthy donors. All the targets that perform well in the microsampling device also show good long-term stability when stored at room temperature for up to 232 days, further showcasing the potential benefits of collecting samples in a dry format.