the present invention has the advantage that separation of cells from secreted proteins and waste products is simplified since both anchorage dependent and suspension cells remain trapped in carrier material 16 during the culture process many anchorage dependent cell lines have been attached to carrier material 16 these include vero surprisingly many suspension lines have also been attached to the carrier material 16 such as hydridomas e g da 4 4 and insect lines e g tn 368 and sf 9 those skilled in the art would recognize that other types of cells can be propagated with the reactors of the present invention fig5 8 illustrate alternate shapes of carrier 16 upper surface 70 of carrier 16 can have a triangular shape as shown in fig5 or upper surface 80 can have a square shape as shown in fig6 alternatively upper surface 90 of carrier 16 can have a hexagonal shape as shown in fig7 in the above carriers lower surface 65 is correspondingly shaped to the shape of the upper surface it will be appreciated that other shapes could be used for carrier 16 fig8 a and 8b illustrate an alternative embodiment of the carrier shown as carrier 200 concentric contoured upper surface 202 204 206 are raised above respective lower surfaces 208 and 210 this embodiment has the advantage of channelling of medium in grooves 212 and 214 the reactor design of the present invention has the advantage of reducing channelling through the packed bed and providing uniformity of flow in the reactor the use of the carrier in a packed bed has the advantage of supporting propagation of hybridomas and promoting cell growth at a high cell density per unit of the reactor hybridomas can.