130 results about "Sequence variation" patented technology

The invention provides methods for determining genome-wide sequence variations associated with a phenotype of a species in a hypothesis-free manner. In the methods of the invention, a set of restriction fragments for each of a sub-population of individuals having the phenotype are generated by digesting nucleic acids from the individual using one or more different restriction enzymes. A set of restriction sequence tags for the individual is then determined from the set of restriction fragments. The restriction sequence tags for the sub-population of organisms are compared and grouped into one or more groups, each of which comprising restriction sequence tags that comprise homologous sequences. The obtained one or more groups of restriction sequence tags identify the sequence variations associated with the phenotype. The methods of the invention can be used for, e.g., analysis of large numbers of sequence variants in many patient samples to identify subtle genetic risk factors.

The present invention provides a technology called Pulse-Multiline Excitation or PME. This technology provides a novel approach to fluorescence detection with application for high-throughput identification of informative SNPs, which could lead to more accurate diagnosis of inherited disease, better prognosis of risk susceptibilities, or identification of sporadic mutations. The PME technology has two main advantages that significantly increase fluorescence sensitivity: (1) optimal excitation of all fluorophores in the genomic assay and (2) “color-blind” detection, which collects considerably more light than standard wavelength resolved detection. Successful implementation of the PME technology will have broad application for routine usage in clinical diagnostics, forensics, and general sequencing methodologies and will have the capability, flexibility, and portability of targeted sequence variation assays for a large majority of the population.

Aspects of the invention relate to the design and synthesis of nucleic acid libraries. Certain embodiments relate to the design and synthesis of nucleic acid libraries that express polypeptides. In some embodiments, the invention provides methods for analyzing polypeptide sequences and identifying those that may confer undesirable properties in vivo (e.g., poor solubility, high immunogenicity, low stability, etc.). In some embodiments, the invention provides methods for synthesizing a library of nucleic acids having predetermined sequences (e.g., a library of nucleic acids that encode polypeptides having related sequences with predetermined sequence variations).

The invention discloses a method for detecting mutation information in a multiplex amplification sequencing product of a genome. The method comprises steps as follows: sequencing data are subjected to quality assessment and preprocessing; a recognizable sequencing sequence is selected for sequence assembling; the recognizable sequencing sequence or a sequence obtained through assembling is compared with a reference gene sequence, and preliminary variation information is obtained; fine calibration of sequence variation is performed according to different types of conditions; a calibrated sequencing fragment is obtained; the homozygosis or heterozygosis state of a target fragment is obtained according to the type of the sequencing fragment with the highest abundance; finally, the mutation information in the multiplex amplification sequencing product of the genome is obtained. By means of the method, the amplification product can be rapidly, efficiently and accurately recognized, and the calculation resources are saved; the sequence assembling process is compatible, and the problem of reduction of the quality value of basic groups produced in the sequencing process can be effectively solved; the homozygosis/heterozygosis state of variation information can be more effectively and stably judged, and random errors introduced in the PCR (polymerase chain reaction) process and the sequencing process are eliminated.

The present invention is directed to various methods for detecting DNA sequence differences, including single nucleotide mutations or polymorphisms, one or more nucleotide insertions, and one or more nucleotide deletions. Labeled heteroduplex PCR fragments containing base mismatches are prepared. Endonuclease cleaves the heteroduplex PCR fragments both at the position containing the variation (one or more mismatched bases) and, to a lesser extent, at non-variant (perfectly matched) positions. Ligation of the cleavage products with a DNA ligase corrects non-variant cleavages and thus substantially reduces background. This is then followed by a detection step in which the reaction products are detected, and the position of the sequence variations are determined.

In some embodiments, the present inventions relates generally to compositions, methods and kits for use in discriminating sequence variation between different alleles. More specifically, in some embodiments, the present invention provides for compositions, methods and kits for quantitating rare (e.g., mutant) allelic variants, such as SNPs, or nucleotide (NT) insertions or deletions, in samples comprising abundant (e.g., wild type) allelic variants with high specificity and selectivity. In particular, in some embodiments, the invention relates to a highly selective method for mutation detection referred to as competitive allele-specific TaqMan PCR ('cast-PCR').

This invention relates to ‘genome partitioning’ and nucleic library construction, for example for sequence variation discovery and screening. The method employs a plurality of restriction enzymes in order to reliably reproduce a representative partition of the entirety of a sample nucleic acid based on the restriction ends of one or more ‘layers’ of the fragments present. In preferred embodiments there is provided a method for producing a nucleic acid library, which library contains a plurality of different nucleic acid fragments, the method comprising: (i) digesting the sample nucleic acid with a plurality of different restriction enzymes to generate a plurality of different layers of fragments, wherein each layer is a group of fragments having a unique combination of restriction ends, and wherein the combination of layers represents the entirety of the sample nucleic acid, (ii) optionally purifying said fragments, (iii) selecting a desired sub-set of layers according to the unique restriction ends of said layers, (iv) ligating said sub-set of layers into vectors adapted to receive it, (v) transforming host cells with the vectors (vi) culturing said host cells to provide said library containing said partition of the sample nucleic acid. The invention also provides systems, methods and functions for designing and optimising such libraries, and genotyping ‘chips’ based on the genome partitioning methods.

We describe here an in vitro method of redistributing sequence variations between non-identical polynucleotide sequences, by making a heteroduplex polynucleotide from two non-identical polynucleotides; introducing a nick in one strand at or near a base pair mismatch site; removing mismatched base(s) from the mismatch site where the nick occurred; and using the opposite strand as template to replace the removed base(s) with bases that complement base(s) in the first strand. By this method, information is transferred from one strand to the other at sites of mismatch.

Provided herein are optimized methods for performing multiplexed detection of a plurality of sequence variations. Also provided are methods for performing multiplexed amplification of target nucleic acid.

Certain sequence variants have been found to be useful for correcting Prostate Specific Antigen levels in humans. The invention provides diagnostic applications based on such correction, including methods of diagnosis of prostate cancer.

The present invention provides improved methods, compositions and kits for short read next generation sequencing (NGS). The methods, compositions and kits of the present invention enable phasing of two or more nucleic acid sequences in a sample, i.e. determining whether the nucleic acid sequences (typically comprising regions of sequence variation) are located on the same chromosome and/or the same chromosomal fragment. Phasing information is obtained by performing multiple, successive sequencing reactions from the same immobilized nucleic acid template. The methods, compositions and kits provided herein are useful, for example, for haplotyping, SNP phasing, or for determining downstream exons in RNA-seq.

A step-wise integrated process for identifying sequence variations in polynucleotide sequences is disclosed. The identification process is composed of three stages, including allele specific hybridization assays of known sequence variations (Stage I), sequence variation locating assays (Stage II), and direct sequencing (Stage III). The methods can be used for efficient and accurate detection of mutations in any test gene sample.

The invention provides a primer and a probe for detecting drug resistance genes mecA in methicillin-resistant staphylococcus aureus (MRSA). The invention also provides a method and a detection kit for detecting drug resistance genes mecA in MRSA. According to the invention, the conserved sequence part of drug resistance genes mecA is directly detected without being affected by the mecA gene variation of strains, and a result is a gold standard of MRSA diagnosis. The specific primer and the probe provided by the invention are applicable to currently known strains containing sequence variation.

In some embodiments, the present invention generally relates to compositions, methods and kits for distinguishing sequence differences between different alleles. More specifically, in some embodiments, the present invention provides methods for quantifying rare (e.g., mutant) alleles in samples containing abundant (e.g., wild-type) allelic variants with high specificity and selectivity. Compositions, methods and kits for genetic variants such as SNP or nucleotide (NT) insertion or deletion. In particular, in some embodiments, the present invention relates to a highly selective method for detecting mutations known as competitive allele-specific TaqMan PCR ("cast-PCR").

An embodiment of a method for detecting low frequency occurrence of one or more HIV sequence variants associated with integrase is described that comprises the steps of: (a) generating a cDNA species from a plurality of RNA molecules in an HIV sample population; (b) amplifying a plurality of first amplicons from the cDNA species, wherein each first amplicon is amplified with a pair of nucleic acid primers; (c) clonally amplifying the amplified copies of the first amplicons to produce a plurality of second amplicons; (d) determining a nucleic acid sequence composition of the second amplicons; (e) detecting one or more sequence variants that occur at a frequency of 5% or less in the nucleic acid sequence composition of the second amplicons; and (f) correlating the detected sequence variants with variation associated with HIV integrase.