HYBRIDIZATION-BASED AFFINITY PARTITIONING OF NUCLEIC-ACIDS USING PEG-COUPLED OLIGONUCLEOTIDES

Polyethylene glycol (PEG)-coupled oligonucleotides are partitioned in an aqueous two-phase system PEG/dextran. The affinity of the oligonucl eotide for the PEG-rich phase increases proportionally to the length o f the coupled PEG polymer. After hybridization, the PEG-coupled oligon ucleotide is able to force a complementary nucleic acid strand into th e PEG-rich phase. This property can be used for the sequence-specific isolation of nucleic acids through hybridization-based affinity partit ioning. The dependence of the partition coefficient in this system on various parameters is described. The application of this principle to multistage chromatographic separations is demonstrated.