The CAP³ integrates a continuous bioreactor with a viable-cell-selective retention system and a continuous capturing system for protein products. This is a fully continuous bio-production platform. The process is sterile and fast, hence the protein product is degraded to a much lower extent than for the equivalent batch system. The stabilized, concentrated protein solution is then fed either continuously or batch-wise onto a second P-CAC (Preparative Continuous Annular Chromatography), where the protein is further purified for final lyophilization.