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