Microscopy approaches to study extracellular vesicles.

ABSTRACT

BACKGROUND: Extracellular vesicles (EVs) have drawn the attention of both biological researchers and clinical physicians due to their function in mediating cell-to-cell communication and relevance as potential diagnostic markers. Since their discovery, the small size and heterogeneity of EVs has posed a hindrance to their characterization as well as to the definition of their biological significance. SCOPE OF THE REVIEW Recent technological advances have considerably expanded the tools available for EV studies. In particular, the combination of novel microscope setups with high resolution imaging and the flexibility in EV labelling allows for the precise detection and characterization of the molecular composition of single EVs. Here we will review the microscopy techniques that have been applied to unravel the mechanism of EV-mediated intercellular communication and to study their molecular composition. MAJOR CONCLUSIONS: Microscopy technologies have largely contributed to our understanding of molecular processes, including EV biology. As we discuss in this review, careful experimental planning is necessary to identify the most appropriate technique to use to answer a specific question. GENERAL SIGNIFICANCE: The considerations regarding microscopy and experimental planning that are discussed here are applicable to the characterization of other small structures, including synthetic nanovectors and viruses.