After introducing {HEAD ~ these antibody genes} in {TAIL ~ the host cells}, cells expressing the antibody can be identified and selected 
in
After introducing { HEAD ~ these antibody genes } in { TAIL ~ the host cells } , cells expressing the antibody can be identified and selected
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH