Mammalian cell culture processes used in the production of monoclonal and recombinant proteins require orthogonal steps in the downstream process to clear virus. Virus filtration is a common, size exclusion-based method in these processes. Initially, tangential flow products were used, but as a result of new-generation virus filtration products, most operations are now constant-pressure, normal-flow operations that can be executed in a single shift operation. The virus filtration step toward the end of the downstream process is now yielding increased protein concentrations…