Our platform, developed in Princeton's Department of Chemistry, combines two state-of-the-art technologies: 3D multi-resolution imaging (3DMRM) and nanoparticle valency sorting. 3DMRM enables the direct and real-time observation of mechanistic actions of a single nanoparticle interacting with and entering a single live cell with 10-nm spatial resolution in three dimensions and 10-μs time resolution. The second technology, Nanoparticle valency sorting, allows the user to identify and analyze the surface ligands and stoichiometry of the nanoparticle. Combining them allows the user to gain mechanistic insights by direct observations of nanoparticles interacting with live cells. The nanoparticle could be a biological, a virus, a lipid nanoparticle (LNP), or an exosome. This platform will enable a massive leap forward in understanding how and why LNP formulations work and could enable equally massive breakthroughs in related research fields such as exosomes or virology.