49results about How to "Improve Sequencing Accuracy" patented technology

The invention provides methods for improving the accuracy of a sequencing-by-synthesis reaction by sequencing at least a portion of a template and at least a portion of template complementary sequence.

Compositions, kits, methods and systems for nucleotide sequencing comprising producing polymerase reactions that exhibit two kinetically observable steps within an observable phase of the polymerase reaction. Two slow step systems can be produced, for example, by selecting the appropriate polymerase enzyme, polymerase reaction conditions including cofactors, and polymerase reaction substrates including the primed template and nucleotides.

The invention provides molecules and methods for nucleic acid synthesis reactions useful in sequencing-by-synthesis processes.

The invention discloses a graphene nanopore-microcavity-solid-state nanopore structure based DNA sequencing device and a method. The sequencing device is mainly composed of a graphene nanopore-equipped graphene microstrip, an inverted pyramid-shaped microcavity in a silicon-based substrate, and a solid-state nanopore at the top of the microcavity. During sequencing, a sequencing reaction chamber is divided into two parts by the graphene nanopore-microcavity-solid-state nanopore structure. A single-stranded DNA molecule passes through the graphene nanopore linearly under the effect of an electrostatic field, then enters the inverted pyramid-shaped microcavity, and finally comes out from the solid-state nanopore. Weak current measuring equipment is utilized to measure longitudinal ionic current blocking caused by the DNA molecule passing activity in the nanopore and the transverse conductance change around the nanopore in the graphene microstrip. Further, a synchronous data recording and processing system is employed for analytical calculation of bi-directional data, thus realizing sequence analysis of the single-stranded DNA molecule.

The invention discloses an adapter for next-generation sequencing. The adapter disclosed in the invention is composed of a single-stranded DNA A and a single-stranded DNA B or composed of a single-stranded DNA C and a single-stranded DNA D. The single-stranded DNA A, from terminal 5' to terminal 3', is as shown in a formula (I), i.e., A1-A3-A2, wherein each nucleotide of A3 is A, T, C or G; the single-stranded DNA B, from terminal 3' to terminal 5', is as shown in a formula (II), i.e., B1-B2, wherein A2 and B2 are complementary, A1 and B1 are not complementary, A3, B1 and A1 are not complementary, the sequences of A1 and A2 are different, and the sequences of B1 and B2 are different; the single-stranded DNA C is composed of A1 and A2; and the single-stranded DNA D is composed of B1, B2 and A3. Experimental results show that the adapter provided by the invention can easily and efficiently reduce false positive mutation in next-generation sequencing so as to realize more sensitive detection of low-frequency mutation in heterogeneous mixed samples like heterogeneous samples and chimera samples of tumors.

The present invention provides a hairpin-like adaptor, a construct and a method for characterizing a double-stranded target polynucleotide. The hairpin-like adaptor comprises a first single strand and a second single strand which are respectively connected with a template strand and a complementary strand of the double-strand target polynucleotide, and the first single strand and the second single strand form at least one double-strand nucleic acid region which is used for enabling the complementary strand to be close to a transmembrane pore after the template strand passes through the transmembrane pore. Also provided are a construct comprising the hairpin-like adapter, as well as a method, a kit, and the like for characterizing double-stranded target polynucleotides. The characterization method disclosed by the invention has many advantages, such as balancing the translocation speed of the template strand and the complementary strand of the target polynucleotide, improving the sequencing accuracy and the like.

A method and a device for determining a nucleotide sequence are proposed. The method comprises immobilising looped fragments of a nucleic acid and a polymerase on a sensor surface and adding a mixture of unlabelled nucleotides onto the sensor surface. Moreover, in the mixture added, one nucleotide type is present at a much lower concentration compared to the other nucleotides. Time intervals between each of the charge separation events are determined and the mixture addition and the registration steps are repeated. Moreover, at each repetition, the nucleotide type present at a much lower concentration compared to the other nucleotides in the mixture added is changed. The nucleotide sequence of a nucleic acid molecule is determined by the analysis of the time intervals between each of the charge separation events registered, which result from the insertion, facilitated by the polymerase, of said unlabelled nucleotides into the growing nucleic acid chain. The device comprises a matrix having a plurality of sensor cells, and a digital-analog circuit, a microfluidic apparatus for feeding working solutions to the sensors, and data processing and display means.

The present invention relates to a method for assembly of nucleic acid sequence data comprising nucleic acid fragment reads into (a) contiguous nucleotide sequence segment(s), comprising the steps of: (a) obtaining a plurality of nucleic acid sequence data from a plurality of nucleic acid fragment reads; (b) aligning said plurality of nucleic acid sequence data to a reference sequence; (c) detecting one or more gaps or regions of non-assembly, or non-matching with the reference sequence in the alignment output of step (b); (d) performing de novo sequence assembly of nucleic acid sequence data mapping to said gaps or regions of non-assembly; and (e) combining the alignment output of step (b) and the assembly output of step (d) in order to obtain (a) contiguous nucleotide sequence segment(s). In addition, a corresponding program element or computer program for assembly of nucleic acid sequence data and a sequence assembly system for transforming nucleic acid sequence data comprising nucleic acid fragment reads into (a) contiguous nucleotide sequence segment(s) is provided.

The invention discloses a specially modified nucleotide as well as an application thereof in high-throughput sequencing. A fluorescence marked group of the nucleotide and a nucleotide matrix are linked through a linker arm containing a vicinal diol bond; vicinal diol hydroxyl is oxidized by a strong oxidant, so that a single bond adjacent to carbon is broken off and a fluorescent group is chemically cut simply and effectively; the same template to be sequenced is subjected to sequencing reactions in two groups, each sequencing is finished by two nucleotide dNTPs cycles marked by two pairs of different fluorescences; in a mode that each nucleotide can only be used once in one cycle, a code composed of a nucleotide fragment is obtained by each sequencing reaction, and nucleotide sequence information composed of a group of codes is obtained after the first group of sequencing reaction is finished; then the second group of sequencing reaction is performed to obtain a plurality of code information ranked by the second group of sequencing reaction; the two groups of code information are encoded according to the sequencing order, and the two groups of encoded information are combined to form the specific base sequence of a nucleotide fragment to be sequenced.

Presented herein are techniques for indexing of nucleic acid, e.g., for use in conjunction with sequencing. The techniques include generating indexed nucleic acid fragments from an individual sample, whereby the index sequence incorporated into each index site of the nucleic acid fragment is selected from a plurality of distinguishable of index sequences and such that the population of generated nucleic acid fragments represents each index sequence from the plurality. In this manner, the generated indexed nucleic acid fragments from a single sample are indexed with a diverse mix of index sequences that reduce misassignment due to index read errors associated with low sequence diversity.

The invention provides a linker sequence and an application thereof. The linker sequence comprises a molecular tag composed of a plurality of bases and sequencing linkers based on sequencing platforms; the molecular tag is located at the 3' end of the sequencing linker; and the linker sequence is linked to fragmented DNA by the molecular tag. The molecular tag composed of the plurality of bases iscombined with the sequencing linkers based on different sequencing platforms, and the constructed linker sequence is connected to one end and/or two ends of the fragmented DNA in the early stage of library construction, so that the marking effect on an original DNA fragment is realized; after the sequencing linkers are connected, the DNA is directly subjected to computer sequencing, so that an original sequence is reserved, and the technical effect of tracing the original source of the DNA fragment is achieved; and repeated fragments in the read length are removed according to the molecular tag in a sequencing result analysis process, and the sequencing accuracy is improved.

The invention discloses a targeted capture sequencing detection method for pathogenic microorganisms of a respiratory system. The method comprises the following steps of: S1, acquiring a genome sequence of the pathogenic microorganisms of the respiratory system, and acquiring a specific gene sequence and a non-specific gene sequence according to the genome sequence; and S2, collecting a real pathogenic sample of the respiratory system, introducing a first mutagenesis mechanism into a half component of the pathogenic sample of the respiratory system to obtain a pathogenic mutagenesis sample of the respiratory system, and constructing a pathogenic microorganism sequencing library based on the pathogenic sample of the respiratory system and the pathogenic mutagenesis sample of the respiratory system. According to the method, a mutation mechanism is introduced into the preparation of the pathogenic microorganism sequencing library to simulate a microorganism mutation process, so that the gene sequence abundance of the microorganisms is increased, a sequencing result of the mutated virus microorganisms is prevented from being false negative, and the sequencing accuracy is improved.

Compositions, devices, systems and methods for increasing the signal to noise ratio (SNR) and/or enhancing photoprotection in an illuminated analytical reaction by addition of one or more signal detection assay (SDA)-enhancing agents to the reaction mixture.

The invention discloses a DNA sequencing device, a solid-state nanopore array and a preparation method of the solid-state nanopore array. The solid-state nanopore array comprises a plurality of pyramids etched on a silicon wafer, silicon oxide grows below each pyramid, silicon nitride is deposited below the silicon oxide, and a first metal electrode is- evaporated below the silicon nitride; secondmetal electrodes are evaporated on the two sides of each pyramid, an inverted pyramid-shaped micro-cavity is formed between the second metal electrodes on the two sides of the adjacent pyramids, a solid-state nanopore is formed in the tower top of each inverted pyramid-shaped micro-cavity, and each solid-state nanopore forms a solid-state nanopore array; the first metal electrode, a variable resistor, a current measuring device, a power supply and the second metal electrodes form a plurality of longitudinal weak current measuring loops; and by adjusting the variable resistor, the current measuring device measures the longitudinal weak current of the longitudinal weak current measuring loops to sequence a DNA sequence passing through the solid-state nanopore array. According to the embodiment of the invention, the DNA sequencing precision and sequencing efficiency can be improved.