Project Summary This proposal seeks funding for the acquisition of an Electrical/Asymmetric Flow Field-Flow Fractionation (E/AF4) system with static and dynamic light scattering detection. This instrument provides state-of-the-art capabilities for integrated separation and characterization of wide range of materials used in modern biomedical research, including proteins and multi-protein complexes, extracellular vesicles, viruses and vaccines, synthetic nanoparticles, and polymeric nanocarriers. The system has analytical and preparative capabilities for high-resolution separation of particles 1 nm-1 m in size and directly and precisely measures and particle size, mass, and zeta potential. Moreover, shape polydispersity indices can be calculated from the mass and size measurements. These capabilities are required by many research projects currently underway at Northwestern University including, but not limited to, the 14 NIH-funded projects described in detail in this application. These projects encompass studies addressing various aspects of genomic organization and function, structure-activity studies to identify and characterize new molecular targets for anti-cancer drugs, and nanotechnology projects pursuing innovative approaches for targeted therapies. A total of 10 prospective major (9 with active NIH funding) and 5 minor (3 with active NIH funding) users are requesting these capabilities. This type of equipment does not exist at Northwestern University or in any core facility in the Chicago area. The instrument will be integrated in the Keck Biophysics Facility, a well-known resource for shared equipment and technical expertise at Northwestern. The facility has a 24-year track record of keeping a diverse collection of high-end research instruments operational and accessible and facilitating the production of large amounts of first- rate science.