PROJECT SUMMARY/ABSTRACT The aim of this project is to acquire a Particle Metrix ZetaView QUATT to characterize small vesicles and particles by nanoparticle tracking analysis (NTA). The University of Delaware (UD) Bio-Imaging Center and its satellite Flow Cytometry Core currently provide nanoparticle characterization of extracellular vesicles (EVs), viruses, virus-like particles, and other nanoparticles used for drug delivery with electron microscopy and flow cytometry. These approaches are invariably complemented and/or validated by NTA to determine size distribution, concentration, and zeta-potential. Despite the ubiquity of the NTA approach, there are currently no NTA systems in a fee-for-service core facility in Delaware. This project aims to fill this critical gap in capabilities by placing the ZetaView NTA system in the UD Bio-Imaging Center, which will ensure that it is easily accessible and well-maintained by core facility staff scientists. Bio-Imaging Center staff will also train users how to run their own samples on the ZetaView and also provide NTA on the ZetaView as an “add-on” service for individuals submitting EV or nanoparticle samples for electron microscopy and flow cytometry services. Therefore, the ZetaView will directly complement recent investments in these technologies and further advance our ability to support research on EV release in bone marrow cells, cancer cells, pathogenic microbes, and nanoparticles developed from viruses, assembled peptides, and fabricated nano-vesicles.