Patent ID: 7572579

Claim:
A screening method for an RNase H inhibitor of a reverse transcriptase, comprising; (a) incubating a substrate which is a primer hybridized to a template, a metal ion and a reverse transcriptase to form a complex, (b) adding a test substance after the process (a) and further incubating, and (c) adding dNTPs after process (b) to initiate DNA synthesis, (d) measuring the amount of nucleic acid cleaved from the template after the process (c), and (e) comparing the value from step (d) to a control lacking the test substance provided that: the template is 5′-NRWXZ-3′ and the primer is 3′-Y-5′, the template is 5′-NRWX-3′ and the primer is 3′-YZ-5′, or the 3′ end of the template 5′-NRWXZ-3′ is linked to the 5′ end of primer 3′-Y-5′ to be a single strand to form -substrate 5′-NRWXZY-3′, wherein, N is present or absent, and if present N is a nucleic acid R is RNA, and the total length of N plus R is 14 mer or more, W is present or absent and if present W is DNA or a chimeric nucleic acid, X is a nucleic acid 15 or more nucleotides long, Y is a nucleic acid with the same length as X to which Y hybridizes; wherein if X is DNA, then Y is DNA; if X is RNA, then Y is RNA; and if X is a chimeric nucleic acid, then Y is a chimeric nucleic acid having complementary sequences and whose sugars of pair nucleotides are the same; Z is present or absents and if present, is a nucleic acid.