Provided herein is a method of using transposition to improve methods of sequencing RNA molecules. Provided herein is a method of tagging nucleic acid duplexes, such as DNA:RNA duplexes or DNA:DNA duplexes. The method includes the steps of providing a transposase and a transposon composition, providing one or more nucleic acid duplexes immobilized on a support, and contacting the transposase and transposon composition with the one or more nucleic acid duplexes under conditions wherein the one or more nucleic acid duplexes and transposon composition undergo a transposition reaction to produce one or more tagged nucleic acid duplexes, wherein the transposon composition comprises a double stranded nucleic acid molecule comprising a transferred strand and a non-transferred strand.