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