Abstract: Computer systems, computer readable media, and computer methods for obtaining, calling, and assembling nucleic acid sequences are presented. In some aspects the invention includes the sequencing of template constructs that comprise double stranded portions in partially contiguous constructs, to provide for single molecule consensus sequence determination through one or both of sequencing sense and antisense strands in the same molecule.

Abstract: Compositions, methods and systems are provided for the isolation of polymerase-nucleic acid complexes. Complexes can be separated from free enzyme by using hook molecules to target single stranded regions on the nucleic acid. Hook oligonucleotides are used to capture polymerase nucleic acid complexes where the nucleic acids comprise circular nucleic acids having a double stranded central region with hairpin regions on each end. Methods for loading such complexes onto substrates and for single molecule sequencing of such complexes are also provided.

Abstract: Methods obtaining a single molecule consensus sequence for a single template molecule, and for obtaining a plurality of single molecule consensus sequences for a plurality of single template molecules is provided. Template molecules having two complementary regions connected with a linker are sequenced. A single read from each template molecule can be obtained, the read containing sequence information for each of the complementary regions. Single molecule consensus sequences can be determined from these reads by comparing the sequence information of the two complementary regions.

Abstract: Methods, compositions, and systems are provided that allow for reliable sequencing of the initial sequence region of a sequence of interest. The methods of the invention allow for more reliable barcoding of subpopulations of nucleic acids to be sequenced.

Abstract: Compositions and methods for nucleic acid sequencing include template constructs that comprise double stranded portions in a partially or completely contiguous constructs, to provide for redundant sequence determination through one or both of sequencing sense and antisense strands, and iteratively sequencing the entire construct multiple times. Additional sequence components are also optionally included within such template constructs. Methods are also provided for the use and preparation of these constructs as well as sequencing compositions for their application.

Abstract: Methods, compositions, and systems are provided for characterization of modified nucleic acids. In certain preferred embodiments, single molecule sequencing methods are provided for identification of modified nucleotides within nucleic acid sequences. Modifications detectable by the methods provided herein include chemically modified bases, enzymatically modified bases, abasic sites, non-natural bases, secondary structures, and agents bound to a template nucleic acid.

Abstract: Methods, compositions, and systems are provided for characterization of modified nucleic acids. In certain preferred embodiments, single molecule sequencing methods are provided for identification of modified nucleotides within nucleic acid sequences. Modifications detectable by the methods provided herein include chemically modified bases, enzymatically modified bases, abasic sites, non-natural bases, secondary structures, and agents bound to a template nucleic acid.

Abstract: Methods, compositions, and systems are provided for characterization of modified nucleic acids. In certain preferred embodiments, single molecule sequencing methods are provided for identification of modified nucleotides within nucleic acid sequences. Modifications detectable by the methods provided herein include chemically modified bases, enzymatically modified bases, abasic sites, non-natural bases, secondary structures, and agents bound to a template nucleic acid.

Abstract: Provided are methods for sequencing a nucleic acid with a sequencing enzyme, e.g., a polymerase or exonuclease. The sequencing enzyme can optionally be exchanged with a second sequencing enzyme, which continues the sequencing of the nucleic acid. In certain embodiments, a template is fixed to a surface through a template localizing moiety. The template localizing moiety can optionally anneal with the nucleic acid and/or associate with the sequencing enzyme. Also provided are compositions comprising a nucleic acid and a first sequencing enzyme, which can sequence the nucleic acid and optionally exchange with a second sequencing enzyme present in the composition. Compositions in which a template localizing moiety is immobilized on a surface are provided. Also provided are methods for using data from analytical reactions wherein two different enzymes are employed, e.g., at a same or different reaction regions.

Abstract: Compositions and methods for nucleic acid sequencing include template constructs that comprise double stranded portions in a partially or completely contiguous constructs, to provide for redundant sequence determination through one or both of sequencing sense and antisense strands, and iteratively sequencing the entire construct multiple times. Additional sequence components are also optionally included within such template constructs. Methods are also provided for the use and preparation of these constructs as well as sequencing compositions for their application.

Abstract: Methods, compositions, and systems are provided that allow for reliable sequencing of the initial sequence region of a sequence of interest. The methods of the invention allow for more reliable barcoding of subpopulations of nucleic acids to be sequenced.

Abstract: Provided are methods for sequencing a nucleic acid with a sequencing enzyme, e.g., a polymerase or exonuclease. The sequencing enzyme can optionally be exchanged with a second sequencing enzyme, which continues the sequencing of the nucleic acid. In certain embodiments, a template is fixed to a surface through a template localizing moiety. The template localizing moiety can optionally anneal with the nucleic acid and/or associate with the sequencing enzyme. Also provided are compositions comprising a nucleic acid and a first sequencing enzyme, which can sequence the nucleic acid and optionally exchange with a second sequencing enzyme present in the composition. Compositions in which a template localizing moiety is immobilized on a surface are provided. Also provided are methods for using data from analytical reactions wherein two different enzymes are employed, e.g., at a same or different reaction regions.

Abstract: Compositions, methods and systems are provided for the isolation of polymerase-nucleic acid complexes. Complexes can be separated from free enzyme by using hook molecules to target single stranded regions on the nucleic acid. Hook oligonucleotides are used to capture polymerase nucleic acid complexes where the nucleic acids comprise circular nucleic acids having a double stranded central region with hairpin regions on each end. Methods for loading such complexes onto substrates and for single molecule sequencing of such complexes are also provided.

Abstract: Compositions, methods and systems are provided for the isolation of polymerase-nucleic acid complexes. Complexes can be separated from free enzyme by using hook molecules to target single stranded regions on the nucleic acid. Active complexes can be isolated from mixtures having both active and inactive complexes by initiating nucleic acid synthesis so as to open up a portion of a double stranded region rendering that region single stranded. Hook molecules are targeted to bind the sequences that are thus exposed. The hook molecules bound to active polymerase-nucleic acid complex are isolated, and the active polymerase-nucleic acid complexes released.

Abstract: Methods, compositions, and systems are provided for characterization of modified nucleic acids. In certain preferred embodiments, single molecule sequencing methods are provided for identification of modified nucleotides within nucleic acid sequences. Modifications detectable by the methods provided herein include chemically modified bases, enzymatically modified bases, abasic sites, non-natural bases, secondary structures, and agents bound to a template nucleic acid.

Abstract: Compositions and methods for nucleic acid sequencing include template constructs that comprise double stranded portions in a partially or completely contiguous constructs, to provide for redundant sequence determination through one or both of sequencing sense and antisense strands, and iteratively sequencing the entire construct multiple times. Additional sequence components are also optionally included within such template constructs. Methods are also provided for the use and preparation of these constructs as well as sequencing compositions for their application.

Abstract: Provided are methods and compositions for the production of linear single-stranded nucleic acids, which can be used as templates in high-throughput sequencing systems. Also provided are methods and compositions for the production of closed single-stranded nucleic acid loops, which can be used as templates in high-throughput sequencing systems.

Abstract: Provided are methods for sequencing a nucleic acid that include fixing a template to a surface through a template localizing moiety and sequencing the nucleic acid with a sequencing enzyme, e.g. a polymerase or exonuclease. The sequencing enzyme can optionally be exchanged with a second sequencing enzyme, which continues the sequencing of the nucleic acid. The template localizing moiety can optionally anneal with the nucleic acid and/or associate with the sequencing enzyme. Also provided are compositions comprising a nucleic acid fixed to a surface via a template localizing moiety, and a first sequencing enzyme, which can sequence the nucleic acid and optionally exchange with a second sequencing enzyme present in the composition. Compositions in which a template localizing moiety is immobilized on a surface are provided. Compositions for sequencing reactions are provided. Also provided are sequencing systems comprising reaction regions in which or near which template localizing moieties are immobilized.

Abstract: Compositions and methods for nucleic acid sequencing include template constructs that comprise double stranded portions in a partially or completely contiguous constructs, to provide for redundant sequence determination through one or both of sequencing sense and antisense strands, and iteratively sequencing the entire construct multiple times. Additional sequence components are also optionally included within such template constructs. Methods are also provided for the use and preparation of these constructs as well as sequencing compositions for their application.

Abstract: Methods, devices, and systems for performing intermittent detection during analytical reactions are provided. Such methods facilitate collection of reaction data from disparate reaction times. Further, such methods are useful for reducing photo-induced damage of one or more reactants in an illuminated analytical reaction at a given reaction time. In preferred embodiments, the reaction mixture is subjected to at least one illuminated and non-illuminated period and allowed to proceed such that the time in which the reaction mixture is illuminated is less than a photo-induced damage threshold period.