Preparation of conjugates between oligonucleotides and N-vinylpyrrolidone/N-acryloxysuccinimide copolymers and applications in nucleic acid assays to improve sensitivity.

A simple approach has been developed to prepare conjugates between oligodeoxyribonucleotides (ODNs) and linear copolymers of N-vinylpyrrolidone (NVP)/N-acryloxysuccinimide (NAS). These conjugates were of higher than expected molecular weight, as determined by light scattering. Side reactions between amino groups on heterocyclic bases, especially of cytosine, are proposed to explain the formation of aggregates. ODN-NVP/NAS conjugates used in both capture and detection steps in sandwich hybridization increased assay sensitivity. Sensitivity to 10(7) DNA molecules/mL was reached for a 2.3 kb PCR fragment of hepatitis B virus (HBV) genomic DNA.