comparing incorporation by {HEAD ~ HIV RT} of {TAIL ~ said analog} with incorporation by a mammalian DNA polymerase, therefrom determining whether said analog is incorporated preferentially by HIV RT 
comparing incorporation by { HEAD ~ HIV RT } of { TAIL ~ said analog } with incorporation by a mammalian DNA polymerase , therefrom determining whether said analog is incorporated preferentially by HIV RT
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH