A U.S. Patent for “Tangential Flow Depth Filtration Systems and Methods of Filtration Using the Same” was awarded to Repligen on September 8th, 2020. The present invention is a bioprocessing system comprising: a process vessel; a tangential flow depth filtration (TFDF) unit comprising a thick-walled hollow fiber formed from at least one polymer and comprising a porous wall defining a lumen that is in fluid communication with the process vessel; a permeate fluid outlet in fluid communication with an exterior surface of the porous wall; and a pump in fluid communication with the lumen; wherein a density of the hollow fiber is between 51% and 56% of the density. Learn More