Virus removal processes are extremely important to biological product safety. This study gives a detailed description of the virus removal mechanisms of Planova (TM) filters. These include the following: (1) Mechanism 1: size exclusion, (2) Mechanism 2: constraint by hydrodynamic forces, and (3) Mechanism 3: multistep filtration. The process was studied through the dynamic perspective of virus movement using simulations and experiments. Our results show that Mechanism 2 and Brownian motion are key factors in virus removal of size exclusion-based filtration and can be evaluated by Peclet number. The addition of dynamic perspective makes it possible to describe macroscopic phenomena such as the effects of filtration pressure and solution viscosity on virus removal capabilities. (c) 2014 American Institute of Chemical Engineers AIChE J, 60: 2286-2297, 2014