Abstract: A method. The method includes providing a filter medium comprising a functionalized nonwoven; passing a first fluid containing cells through the filter medium, wherein at least some of the cells are captured by the functionalized nonwoven; passing a second fluid, and optionally a third and/or fourth fluid through the filter medium, wherein the second and/or third and/or fourth fluid disrupts at least one of the captured cells; and recovering an intracellular biological product in the first and/or second and/or third and/or fourth fluid.

Abstract: Described herein is a method of purifying a target molecule from an aqueous biological composition, the method comprising: (a) contacting a cationic polymer and the aqueous biological composition to form a mixture comprising a bio-polymer complex and the target molecule in a liquid, wherein the bio-polymer complex has an average particle diameter of at least 45 micrometers, (b) adding the mixture to a filtering volume of a vessel, wherein the vessel comprises loosely packed staple fibers; (c) allowing the mixture to separate through the loosely packed staple fiber; and (d) collecting a filtrate comprising the target molecule.

Abstract: Described herein is a method of purifying a target molecule from an aqueous biological composition, the method comprising: (a) contacting a cationic polymer and the aqueous biological composition to form a mixture, the mixture comprising a bio-polymer complex and the target non-binding molecule in a liquid, wherein the bio-polymer complex has an average particle diameter of at least 50 micrometers; (b) providing a filtering unit comprising (i) a housing having an inlet and an outlet, (ii) a porous, continuous filter medium which is fluidly connected to the inlet and the outlet, and (iii) a collection region upstream from the porous, continuous filter medium; (c) adding the mixture to the inlet; and (d) allowing the mixture to separate in the filtering unit, whereby the bio-polymer complex collects in the collection region and the target non-binding molecule passes through the filter medium, and wherein the majority of flow of the liquid through the porous, continuous filter medium is not substantially paralle