How do batch, fed-batch and perfusion cell culture differ?

Why

In a batch culture, nutrients run out and waste builds up, so growth stops early and titers are low. Fed-batch solves this by adding feeds, often as bolus additions, during a run that typically lasts 10 to 14 days or more. A 2010 review of antibody processes describes fed-batch as the most widely used mode because it is simple and scalable, with titers that had reached about 10 g per liter.

Perfusion keeps cells in the bioreactor with a retention device, most commonly alternating tangential flow filtration, while medium flows through. A 2021 review on continuous manufacturing notes perfusion gives higher productivity with less buildup of metabolites and impurities. Its main quality advantage is residence time.

In fed-batch, product made on day 2 sits in the warm, protease-containing culture until harvest, which can cause aggregation, fragmentation and other modifications. Perfusion removes product continuously, so it suits labile molecules such as some enzymes and fusion proteins. The trade-offs are that perfusion uses large volumes of medium, is more complex to run and validate, and carries more risk from long run times, such as contamination or cell line drift.

Fed-batch remains the default for robust antibodies, while perfusion is chosen for unstable products, for intensified seed trains or as part of continuous processing.