Nanoparticle size, size distribution, and concentration (count) determination has been a significant analytical challenge. The challenge is acute for the typical sample which contains particles with a wide range of sizes. This webinar discusses a novel implementation of nanoparticle tracking analysis (NTA) that addresses these challenges. Like conventional NTA, this new method tracks the motion of each particle in the sample to determine size. Significant advancements in the optics compared to conventional NTA will be described that allow particles with varying sizes in the same sample to be visualized and accurately quantified. This particle-by-particle detection allows exquisite resolution in determining size distributions along with particle count and, therefore, concentration. Furthermore, the system provides visualization and analysis of nanoparticle kinetic processes, such as dissolution, aggregation and crystallization.