Methods

Process overview

The purification process for this study included an automated and integrated dual-column chromatography step (DCC) (Angarita, 2015), leading into a continuous virus inactivation (VI) step and a final flow-through polishing AEX step. Upstream and downstream of the DCC step were 10L glass vessels to accommodate purification of 50L of cell culture material per day. The process flow path, the connections between each unit operation in the process and the automation to control and acquire the data from all unit operations in parallel, were executed with four 500mL flow kits and the Pilot PAK system from PAK BioSolutions (Virginia, US). The flow path of the process and the PAK flow kits are shown in Figure 1 and Figure 2, respectively. The 50L per day of harvested material was combined from several different perfusion bioreactors that had run prior to this study. The bags were chosen and connected in order to simulate the titer profile of a typical perfusion bioreactor process.