Inoculum propagation in animal cell culture is typically done in a series of batch cultures with increasing cultivation volume until a sufficient cell number is obtained for seeding the final production reactor. Propagation of inoculum in a perfusion culture in disposable Cellbag™ bioreactors can be used to achieve at least 5 to 10-fold higher split ratio compared with traditional cell expansion in batch cultures. This in turn offers the possibility to reduce the number of steps in a seed train.
The WAVE Bioreactor™ 20/50 system has a maximum culture volume of 25 liters; run in perfusion mode, the reactor can directly provide inoculum for working volumes up to 1000 liters. Furthermore perfusion cultures could also be used to seed production reactors at higher cell concentrations, thereby shortening process time and improving facility throughput.
For details on perfusion culture using WAVE Bioreactor systems see the application note: 29-0051-80 (view PDF, above).