US Patent 9139874 Bi-directional sequencing compositions and methods

In some embodiments, methods for obtaining sequence information from a nucleic acid template linked to a support include hybridizing a first primer to a template strand linked to a support, sequencing a portion of the nucleic acid template, thereby forming an extended first primer product that is complementary to a portion of the nucleic acid template. In some embodiments, the method further includes introducing a nick into a portion of the template strand that is hybridized to the extended first primer product, degrading a portion of the template strand from the nick using a degrading agent, where a portion of the extended first primer remains hybridized to an undegraded portion of the template strand, and sequencing at least some of the single-stranded portion of the extended first primer by synthesis.