Tangential viral filtration

A method for removing viral particles from a solution, the method comprising:

• (a) transporting a solution comprising viral particles through a filter unit comprising a filter member;
• (b) capturing a portion of the solution that passes through a filter member in a direction orthogonal to a flow direction of the transported solution through the filter unit;
• (c) transporting a remaining portion of the solution that does not pass through the filter member into a reservoir;
• (d) recirculating a portion of the solution from the reservoir through the filter unit;
• and
• (e) repeating steps (b)-(d) to capture multiple portions of the solution, where each captured solution passes through the filter member,
• wherein the filter member has a thickness and comprises a plurality of channels, and wherein for each of at least 50% of the channels in the filter member, a channel axis is oriented at an angle of between 5 degrees and 85 degrees relative to a thickness direction of the filter member.