Many common perfusion platforms utilize hollow fibers as a cell retention mechanism in order to be able to flow media at an acceptable rate. ATF (Alternating Tangential Flow) tank attachments, for example, are a common perfusion system that use hollow fibers like a filter, retaining and circulating the cells back into the tank while passing the cell product through the membrane into a holding tank. However, there are several distinct advantages to Cell Culture Company’s hollow fiber perfusion bioreactor design when comparing to ATF tank systems: Homogenous Environment, Save on Media Use, Long-term, Stable Production, Easy Protein Retention, and Consistency.