Service offered: Extracellular Vesicle analysis using cryo electron microscopy imaging

The electron microscopy Facility at the Leiden University Medical Center (LUMC), has developed a workflow for analysis of extracellular vesicles (EVs) using automated cryo-electron microscopy (cryo-EM) imaging in combination with supervised machine learning (sML) particle analysis. Using this workflow the abundance and size of EVs and also other particles (lipoproteins, protein aggregates viruses, etc.) in purified samples can be analyzed.

Extracellular vesicles (EVs) are small (~100 nm) cell-derived membrane-surrounded vesicles that carry bioactive molecules and deliver them to recipient cells. EVs are released from all cells in different ways, have variable lipid, protein and nucleic acid contents, and can have different functions. EVs have gained large interest in their use as biomarkers for several diseases. Generation of highly pure and highly concentrated EV samples from human sources is difficult due to relative low abundancy in combination with overlapping physical properties with other particles (lipoproteins, protein complexes, etc.). Most analysis techniques either do not discriminate between EVs and other particles, or detect a specific marker in EVs. Since cryo-EM is the only technique that can directly visualize the lipid bilayer of EVs, and also can detect contaminants and other particles like viruses, lipoproteins and genomic material, it can be a valuable additional technique for the analysis of purified samples.