Industrial scale harvest of proteins from mammalian cell culture by tangential flow filtration

An industrial‐scale methods for harvest of biologically active proteins form mammalian cell culture has been developed using tangential flow filtration. A robust and economical process capable of processing approximately 5000 L conditioned media/h with protein yields in excess of 99% has been achieved. A completely contained system has been designed in which total cell number and viability are maintained throughout the process. The process has successfully been implemented at 1.25 × 104 L scale for the recovery of kilogram quantities of pharmaceutical proteins such as recombinant tissue type plasminogen activator (rt‐PA).