Nucleic acid sample enrichment for sequencing applications

A method of selecting and amplifying polynucleotides on a solid support, comprising:

• a) providing a plurality of amplification oligonucleotides immobilized on a solid support;
• b) hybridizing a population of oligonucleotide probes to a subset of said amplification oligonucleotides, each of said oligonucleotide probes comprising a first portion which is complementary to the amplification oligonucleotides and a second portion which comprises sequence from a selected region of a template polynucleotide;
• c) performing an extension reaction to extend hybridised amplification oligonucleotides to produce a population of support-bound capture oligonucleotides, each capture oligonucleotide in said population comprising a sequence that is complementary to a selected region of a template polynucleotide;
• d) applying a population of template polynucleotides to the solid support under conditions such that the template polynucleotides selectively hybridise to the support-bound capture oligonucleotides;
• e) extending the support-bound capture oligonucleotides that are hybridized to the template polynucleotides, thereby generating extension products complementary to the template polynucleotides;
• f) amplifying the extension products, wherein the amplifying comprises annealing one or more of the immobilised amplification oligonucleotides to one or more of the extension products, thereby producing a solid-phase amplification product;
• and
• g) sequencing a first strand of the solid-phase amplification product of step f) to obtain at least part of the nucleotide sequence of the template polynucleotide.