Pacific Biosciences of California, Inc.

Tyson A Clark

Jonas Korlach

Kevin Travers

Thang Pham

Stephen Wilson Turner

Cheryl Heiner

Arunashree Bhamidipati

Eric Olivares

Erik Miller

Yu-Chih Tsai

Jeremiah Hanes

John Lyle

Jeffrey Wegener

Jon M Sorenson

Patrick Marks

Benjamin A Flusberg

Lei Jia

Austin B Tomaney

Igor D Vilfan

Dale R Webster

Andrey Kislyuk

Jessica Lee

Chuan He

Joseph Puglisi

Xingyu Lu

Liang Zhang

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.

Delaying real-time sequencing

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

Methods are provided for reducing the complexity of a population of nucleic acids prior to performing an analysis of the nucleic acids, e.g., sequence analysis. The methods result in a subset of the initial population enriched for a target region, which is typically located within one or more target fragments. The methods are particularly useful for analyzing populations having a high degree of complexity, e.g., chromosomal-derived DNA, whole genomic DNA, or mRNA populations.

Compositions and methods for selection of 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

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.

Methods and compositions for sequencing modified nucleic acids

Identification of nucleic acid template-linked barcodes comprising nucleic acid modifications

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.

A method for identifying a 5-MeC in a template nucleic is provided. The method comprises providing a template having 5-MeC, converting the 5-MeC into a further modification selected from 5-caC and 5-FC. The converted template is then sequenced, and a change in sequencing is detected that is indicative of the further modification, allowing for identifying the 5-MeC in the template nucleic acid.

Identification of 5-methyl-C in nucleic acid templates

Growing community of inventors

Menlo Park, CA, United States of America

Tyson A Clark