Pacific Biosciences of California, Inc.

Eric Olivares

Jonas Korlach

Kevin Travers

Thang Pham

Tyson A Clark

Arunashree Bhamidipati

Stephen Wilson Turner

Fred C Christians

Adrian Nielsen Fehr

Jon M Sorenson

Jeremy Gray

Yu-Chih Tsai

Ali Bashir

Aj Chmura

Jason Underwood

Pham Thang

Compositions, methods and systems are provided for isolating nucleic acids. A polymerase-nucleic acid complex can be formed by mixing a polymerase enzyme comprising strand displacement activity and a mixture of double stranded nucleic acids. Nucleic acid synthesis can then be initiated by the polymerase enzyme to produce a nascent strand complementary to the first strand, thereby displacing a portion of the second strand. After halting or reducing the rate of nucleic acid synthesis, a hybridizing a hook oligonucleotide can be used hybridize to the nucleic acid through a capture region on the hook oligonucleotide that is complementary to the displaced portion of the second strand. The nucleic acid can then be isolated from the mixture of nucleic acids using the hook oligonucleotide.

Methods for isolating nucleic acids

Compositions, methods and systems are provided for the loading of extended polymerase-nucleic acid complexes onto substrates. Primed polymerase-template complex comprising a polymerase enzyme and a circular nucleic acid template comprising a double stranded region connected at each end by a single-stranded hairpin region are provides in which the circular nucleic acid template comprises at least one reversible pause point. Nucleic acid synthesis is carried out such that a nascent strand is synthesized up to the reversible stop point producing an extended polymerase-template complex. The extended polymerase-template complex is then attached to a substrate. Such attached complexes can be used for single molecule sequencing in which the nucleic acid synthesis is re-initiated such that nucleic acid synthesis continues past the reversible stop point.

Loading extended polymerase-nucleic acid complexes

Compositions, methods and systems are provided for isolating DNA having a modified or unnatural base. Circular DNA fragments, each comprising a double stranded DNA central region and single stranded regions on the ends of the double stranded regions, are obtained. Some of the fragments have one or more modified or unnatural base. The DNA fragments are treated with a primer and a polymerase such that the polymerase extends the primer to copy at least one of the strand of the double stranded region. This results in rendering the other strand single stranded. A binding protein or antibody that is specific to the modified or unnatural base is then used to isolate strands containing the modified or unnatural bases. Methods for loading such complexes onto substrates and for single molecule sequencing of such complexes are also provided.

Isolation of polymerase-nucleic acid complexes

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.

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.

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.

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Union City, CA, United States of America

Eric Olivares