{HEAD ~ The medium} may be used for serum free culture or supplemented with low levels of {TAIL ~ serum} 
{ HEAD ~ The medium } may be used for serum free culture or supplemented with low levels of { TAIL ~ serum }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL