Depth filtration in bioprocessing — new opportunities for an old technology

Depth filtration has a long history in both bioprocessing and water treatment, with the earliest records of water purification by depth filtration dating back 4000 years. The renewed interest in depth filtration for bioprocessing has been driven by the push towards single-use manufacturing technologies along with the increased turbidity arising from improvements in cell density and product titer. This review highlights the key principles, developments, and applications of depth filtration systems, including growing opportunities for use of depth filtration for both initial clarification and for treatment of in-process streams to reduce host cell proteins and remove key foulants to improve the overall performance of the downstream process.