Patent ID: 8288092

Claim:
A process for producing a modified nucleic acid polymer that is a linear nucleic acid, a branched nucleic acid, an inverted nucleic acid, 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, and has decreased thermodynamic stability in binding to complementary sequences as compared to a corresponding unmodified nucleic acid polymer, said process comprising the step of enzymatically incorporating into a nucleic acid sequence at least one modified nucleotide or nucleotide analog having a negatively charged chemical moiety, wherein said modified nucleotide or nucleotide analog comprises a purine or pyrimidine base modified with a negatively charged chemical moiety which comprises carboxylic acid.