PERFUSION & CONCENTRATED PERFUSION

Recirculating hollow fiber systems have been used for a long time with mixed results. The recurring problem with these and all other cell retention systems is the difficulty in scaling up and staying sterile. Many cell retention systems scale up based upon surface area, or a separation chamber of sorts, that upon transfer into a manufacturing environment become very challenging to run efficiently or reliably. Many companies who use internal spin filters or centrifuges, for example, typically invest a considerable amount of time optimizing their often unique installations.

Trying to avoid cell damage or time outside of the reactor in a dead zone are common issues with those systems. These problems are eliminated when the ATF™ System is used as a production platform. The ATF System scales nearly linearly and is simple and quick to install, operate, validate and maintain. With the ATF System process development becomes simple since there is little equipment optimization required so all time can be spent improving media and bioreactor conditions. The ATF System allows significant cell density to be achieved rapidly.

Key benefits include:

• Low shear
• Cells in constant equilibrium with reactor contents
• Encourages faster cell growth

Some cell lines show a decrease in cell size, allowing a faster molecular transfer across the cell wall (increase of surface area to volume ratio). Together these benefits deliver high viability and higher growth rate and thereby lead to a surprising high cell concentration in almost every cell line tested.