Extracellular vesicles (EVs) are secreted nanosized particles with many biological  functions and a broad range of pathological associations. A major technical limitation to  understanding the role of EVs in normal and diseased specimens has been the inability to  visualize the spatial localization of EVs in tissue microenvironments. Here, we use bovine ocular tissue, the vitreous humor, as a model system to study EV imaging. We show that  mammalian tissues crosslinked with conventional formaldehyde solutions result in  significant EV loss, with subsequent reduced or negative EV signals; however, EV escape  can be prevented by additional fixation with 1-ethyl-3-(3-dimethylaminopropyl)  carbodiimide (EDC) that permanently holds these nano-sized particles and allows for  visualization of EVs in normal and cancer tissues in situ.