Increasing CHO cell harvest efficiency with cyclical cake filtration

Efficient clarification of bioreactor harvests remains a critical bottleneck in biomanufacturing, directly impacting throughput, product yield, and operational costs. Current industry practice typically relies on depth filters because they can effectively remove impurities, but they are also prone to fouling, require oversized filter areas, and can reduce product yield due to non-specific adsorption. As a response to some of those shortcomings, alluvial filtration was introduced which uses a diatomaceous earth (DE) cake to protect filter media, maintaining higher flow rates and extending filter life. Alluvial filters can reduce the required filter area, however, the true benefit of cake filtration can only be leveraged when using cyclical cake filtration. This technique uses multi-cycle cloth regeneration, achieving superior throughput and yield while maintaining filtrate clarity. Addition of ion exchange resins further allows for impurity reduction comparable to depth filtration without compromising product recovery. This study examines cyclical cake filtration and compares it with traditional and alluvial depth filtration regarding performance and scalability. Results indicate that cyclical cake filtration reduces required filter area and laboratory footprint, offering substantial economic and environmental benefits for commercial-scale production.