The primary cells are cultivated in a serum free medium comprising a factor selected from {HEAD ~ the group} consisting of growth factors and {TAIL ~ attachment factors} 
consisting of
The primary cells are cultivated in a serum free medium comprising a factor selected from { HEAD ~ the group } consisting of growth factors and { TAIL ~ attachment factors }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL