Comparing digital detection platforms in high sensitivity immune-phenotyping of extracellular vesicles

Despite their clinical potential, Extracellular Vesicles (EVs) struggle to take the sceneas a preeminent source of biomarkers in liquid biopsy. Limitations in the use of EVsorigin from their inherent complexity and heterogeneity and from the sensitivitydemand in detecting low to very low abundant disease-specific sub-populations. Suchneed can be met by digital detection, namely capable to reach the single-molecule sen-sitivity. Here we set to compare, side by side, two digital detection platforms that haverecently gained increasing importance in the field of EVs. The platforms, both com-merciallyavailable,arebasedontheprinciplesoftheSingleParticleInterferometricReflectance Imaging Sensing (SP-IRIS) and the Single Molecule Array technology(SiMoA) respectively. Sensitivity in immune-phenotyping of a well characterized EVsample is reported, discussing possible applicative implications and rationales foralternative or complementary use of the two platforms in biomarker discovery orvalidation.