Disclosed herein is a method of covalently crosslinking DNA strands. In certain aspects, the method comprises incubating a hybridized, double-stranded DNA polynucleotide (dsDNA), comprising a probe strand that comprises an abasic (Ap) residue and an at least partially complementary target strand that comprises a 2′-deoxyadenosine (dA) residue, wherein incubation occurs under conditions that allow for a covalent crosslinking reaction to occur between the Ap residue in the probe strand and the dA residue in the target strand.

Provided herein are compositions, systems and methods for tagging molecular events, reactions, species, etc., but without the need for complex, highly diverse libraries of tagging molecules. Provided are tagging moieties that can have a smaller number, a few, or even a single original “tagging” structure that may be transformed or transformable, in situ, into a collection of larger numbers of unique tagging or “barcode” moieties.

Provided herein are compositions, systems and methods for tagging molecular events, reactions, species, etc., but without the need for complex, highly diverse libraries of tagging molecules. Provided are tagging moieties that can have a smaller number, a few, or even a single original “tagging” structure that may be transformed or transformable, in situ, into a collection of larger numbers of unique tagging or “barcode” moieties.

Provided are methods for preparing a library of target nucleic acid sequences, as well as compositions and uses therefor. Methods comprise contacting a nucleic acid sample with a plurality of adaptors capable of amplification of one or more target nucleic acid sequences under conditions wherein the target nucleic acid(s) undergo a first amplification; digesting the resulting first amplification products; repairing the digested target amplicons; and amplifying the repaired products in a second amplification, thereby producing a library of target nucleic acid sequence. Each of the plurality of adaptor compositions comprise a handle and a targeted nucleic acid sequence and optionally one or more tag sequences. Provided methods may be carried out in a single, addition only workflow reaction, allowing for rapid production of highly multiplexed targeted libraries, optionally including unique tag sequences. Resulting library compositions are useful for a variety of applications, including sequencing applications.

Provided are methods for preparing a library of target nucleic acid sequences, as well as compositions and uses therefor. Methods comprise contacting a nucleic acid sample with a plurality of adaptors capable of amplification of one or more target nucleic acid sequences under conditions wherein the target nucleic acid(s) undergo a first amplification; digesting the resulting first amplification products; repairing the digested target amplicons; and amplifying the repaired products in a second amplification, thereby producing a library of target nucleic acid sequence. Each of the plurality of adaptor compositions comprise a handle and a targeted nucleic acid sequence and optionally one or more tag sequences. Provided methods may be carried out in a single, addition only workflow reaction, allowing for rapid production of highly multiplexed targeted libraries, optionally including unique tag sequences. Resulting library compositions are useful for a variety of applications, including sequencing applications.

Methods, primers and probes are provided for the isothermal amplification and detection, without denaturation, of double stranded nucleic acid targets for polymerase strand displacement amplification (“iSDA”). The methods and compositions disclosed are highly specific for nucleic acid targets with high sensitivity, specificity and speed that allow detection of clinical relevant target levels. The methods and compositions can easily be used to amplify or detect nucleic acid targets in biological samples.

Methods, primers and probes are provided for the isothermal amplification and detection, without denaturation, of double stranded nucleic acid targets for polymerase strand displacement amplification (“iSDA”). The methods and compositions disclosed are highly specific for nucleic acid targets with high sensitivity, specificity and speed that allow detection of clinical relevant target levels. The methods and compositions can easily be used to amplify or detect nucleic acid targets in biological samples.

The invention relates to methods for pairwise sequencing of a polynucleotide template which result in the sequential determination of nucleotide sequence in two distinct and separate regions of the polynucleotide template.

The invention relates to methods for pairwise sequencing of a polynucleotide template which result in the sequential determination of nucleotide sequence in two distinct and separate regions of the polynucleotide template.

The present invention relates to a method of using nanopores to obtain sequence information of sample DNAs in ss test DNAs. The method comprises using speed bumps to stall the ss test DNAs in the nanopores at random positions of the ss test DNAs to obtain sequence information of each and every nucleotides of the sample DNAs, and to construct the whole sequences of the sample DNAs. The present invention also relates to identification and/or isolation of test DNAs having desired sequence(s) using nanopore detectors facilitated by speed bump.