Patent ID: 7713691

Claim:
A process for producing a single-stranded or double stranded modified nucleic acid polymer selected from the group consisting of a linear nucleic acid, branched nucleic acid, an inverted nucleic acid and a peptide-nucleic acid, or a combination of any of the foregoing, wherein said nucleic acid polymer comprises at least one modified purine or pyrimidine base, wherein said purine or pyrimidine base is modified with a negatively charged chemical moiety which comprises carboxylic acid covalently attached to an allyl moiety and wherein said polymer has decreased thermodynamic stability in binding to complementary sequences as compared to a corresponding unmodified nucleic acid polymer comprising the step of enzymatically incorporating into the nucleic acid sequences produced at least one modified nucleotide or nucleotide analog having a negatively charged chemical moiety, wherein said negatively charged chemical moiety comprises carboxylic acid covalently attached to an allyl moiety, wherein said nucleic acid is produced under thermocycling conditions where an annealing step and denaturation step are undertaken at temperatures that are no more than 12° C. apart.