title: Molecular and dimensional profiling of highly purified extracellular vesicles by fluorescence fluctuation spectroscopy.
abstract: Cells secrete extracellular vesicles (EVs) into their microenvironment that act as mediators of intercellular communication under physiological conditions and in this context also actively participate in spreading various diseases. Large efforts are currently made to produce reliable EV samples and to develop, improve, and standardize techniques allowing their biophysical characterization. Here, we used ultrafiltration and size-exclusion chromatography for the isolation and a model-free fluorescence fluctuation analysis for the investigation of the physical and biological properties of EVs secreted by mammalian cells. Our purification strategy produced enriched samples of morphologically intact EVs free of extravesicular proteins and allowed labeling of marker molecules on the vesicle surface for single-vesicle analysis with single-molecule sensitivity. This novel approach provides information on the distribution profile of both EV size and relative expression level of a specific exosomal marker, deciphering the overall heterogeneity of EV preparations.
authors.affiliation: Laboratory of Physical Chemistry of Polymers and Membranes, Ecole Polytechnique Fédérale de Lausanne , Station 6, 1015 Lausanne, Switzerland.
authors.forename: Romain
authors.initials: R
authors.lastname: Wyss
authors.forename: Luigino
authors.initials: L
authors.lastname: Grasso
authors.forename: Camille
authors.initials: C
authors.lastname: Wolf
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Grosse
authors.forename: Davide
authors.initials: D
authors.lastname: Demurtas
authors.forename: Horst
authors.initials: H
authors.lastname: Vogel
mesh_terms: D057809:HEK293 Cells; D006801:Humans; D013050:Spectrometry, Fluorescence / Q000379:methods*