In summaryPerfusion offers great advantages. Before deciding on the right cell retention method, several attributes need to be considered, including costs, the shear forces the cells encounter, how prone the devices are to clogging, and the cell densities that can be achieved.
There is no general answer to the question, which process mode is the most cost-effective, but it has to be asked for any given biopharmaceutical. Costs for process development, medium, bioprocess equipment, and lab-space have to be taken into account. Perfusion is on the rise. Especially when planning a new process or even a whole new bioprocess facility it is for sure worth taking a very close look at it.
 Konstaninov K, Cooney C (2014): White Paper on Continuous Bioprocessing. May 20–21, 2014 Continuous Manufacturing Symposium. Wiley Online Library. DOI 10.1002/jps.24268
 Kropp C, Kempf H, Halloin C, Robles-Diaz D, Franke A, Scheper T, Kinast K, Knorpp T, Joos TO, Haverich A, Martin U, Zweigerdt R, and Olmer R (2016): Impact of Feeding Strategies on the Scalable Expansion of Human Pluripotent Stem Cells in Single-Use Stirred Tank Bioreactors. Stem Cells Transl Med 5 10:1289.