{TAIL ~ A process} 1, in which, in the vessel, {HEAD ~ the stirrer blades} further comprise a material to which the biological material does not substantially adhere 
{ TAIL ~ A process } 1 , in which , in the vessel , { HEAD ~ the stirrer blades } further comprise a material to which the biological material does not substantially adhere
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH REL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH