SC is a conjugated substance that is said {HEAD ~ first member} of {TAIL ~ a specific binding pair} 
SC is a conjugated substance that is said { HEAD ~ first member } of { TAIL ~ a specific binding pair }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL