The cell culture medium comprises {HEAD ~ about 5 to about 150 mM} of {TAIL ~ polar amino acids} 
of
The cell culture medium comprises { HEAD ~ about 5 to about 150 mM } of { TAIL ~ polar amino acids }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL