A method of screening for a nucleoside analog that is incorporated and extended at high efficiency by reverse transcriptase of {TAIL ~ human immunodeficiency virus} and causes {HEAD ~ incorrect base} pairing, said analog incorporated preferentially by HIV RT relative to incorporation by a mammalian DNA polymerase, comprising: 
A method of screening for a nucleoside analog that is incorporated and extended at high efficiency by reverse transcriptase of { TAIL ~ human immunodeficiency virus } and causes { HEAD ~ incorrect base } pairing , said analog incorporated preferentially by HIV RT relative to incorporation by a mammalian DNA polymerase , comprising :
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH