Apparatus for culturing animal cells

An apparatus for the in vitro culture of animal cells to recover secreted proteins of interest therefrom, affording the capability of being readily and predictably scaled up or down to desired protein production rates, comprised of a housed arrangement of culture subunits containing a packed bed of carrier particles, each subunit being fed in parallel from a common culture medium source, and the spent culture fluid from each subunit being directed to a common spent fluid conduit within the housed arrangement. Scale-up or scale-down is effected by addition or subtraction of culture subunits and/or by increase or decrease in carrier particle volume within a subunit while maintaining substantially constant packed bed height.