The present invention provides processes for aseptically processing live mammalian cells in an aqueous medium to produce a cell suspension having a cell density of at least about 10 million cells/mL and cell viability of at least about 90%. These methods comprise a step of reducing the volume of the medium using a tangential flow filter (TFF) having a pore size of greater than 0.1 micron, during which step the trans-membrane pressure (TMP) is maintained at less than about 3 psi and the shear rate is maintained at less than about 4000 sec−1. The invention also provides a complete process for large scale manufacturing mammalian cells for use in a therapeutic composition, and scalable, fully disposable systems for carrying out the process, using readily available disposables and pumps.