{HEAD ~ The method} of identifying nucleic acids, preferably associated with {TAIL ~ other functional units}, which have the facilitative activity described herein is termed Chemi SELEX 
{ HEAD ~ The method } of identifying nucleic acids , preferably associated with { TAIL ~ other functional units } , which have the facilitative activity described herein is termed Chemi SELEX
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH