Moscow State University of Medicine and Dentistry 1 article published in JoVE Immunology and Infection Flow Virometry to Analyze Antigenic Spectra of Virions and Extracellular Vesicles Anush Arakelyan1, Wendy Fitzgerald1, Sonia Zicari1, Murad Vagida2, Jean-Charles Grivel3, Leonid Margolis1 1Section on Intercellular Interactions, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 2Laboratory of Atherothrombosis, Cardiology Department, Moscow State University of Medicine and Dentistry, 3Sidra Medical and Research Center Viruses or extracellular vesicles were immunocaptured with 15 nm magnetic nanoparticles coupled to antibodies recognizing surface antigens. The captured virions or vesicles were labeled with fluorescent antibodies against other surface antigens. The resultant complexes were separated in high magnetic field and analyzed with conventional flow cytometers triggered on fluorescence.