Abstract:
The present disclosure provides methods for determining the ploidy status of an embryo at a chromosome from a sample of DNA from an embryo. The ploidy state is determined by sequencing the DNA from one or more cells biopsied from the embryo, and analyzing the relative amounts of each allele at a plurality of polymorphic loci on the chromosome. In an embodiment, the ploidy state is determined by comparing the observed allele ratios to the expected allele ratios for different ploidy states. In an embodiment, the DNA is selectively amplified at a plurality of polymorphic loci by targeted sequencing. In an embodiment, the mixed sample of DNA may be preferentially enriched at a plurality of polymorphic loci in a way that minimizes the allelic bias.
Abstract:
This disclosure describes, in one aspect, a method for preparing DNA molecule for sequencing. Generally, the method includes fragmenting the DNA molecule into double-stranded fragments; amplifying at least a portion of the double-stranded fragments; circularizing the fragments so that the first end of the fragment comprises a first loop connecting the strands and the second end of the fragment comprises a second loop connecting the strands; annealing a first sequencing primer to the first loop oriented to sequence at least a portion of one strand of the fragment; and annealing a second sequencing primer to the second loop oriented to sequence at least a portion of the other strand of the fragment. In another aspect, this disclosure describes a method for sequencing a DNA molecule. Generally, the method includes fragmenting the DNA molecule into double-stranded fragments; amplifying at least a portion of the double-stranded fragments; circularizing the fragments so that the first end of the fragment comprises a first loop connecting the strands and the second end of the fragment comprises a second loop connecting the strands; and sequencing at least one of the DNA strands.
Abstract:
The present disclosure provides methods and systems for detecting multiple different nucleotides in a sample. In particular, the disclosure provides for detection of multiple different nucleotides in a sample utilizing fewer detection moieties than the number of nucleotides being detected and/or fewer imaging events than the number of nucleotides being detected.
Abstract:
A method for nucleic acid sequencing includes receiving a plurality of observed or measured signals indicative of a parameter observed or measured for a plurality of defined spaces; determining, for at least some of the defined spaces, whether the defined space comprises one or more sample nucleic acids; processing, for at least some of the defined spaces, the observed or measured signal to improve a quality of the observed or measured signal; generating, for at least some of the defined spaces, a set of candidate sequences of bases for the defined space using one or more metrics adapted to associate a score or penalty to the candidate sequences of bases; and selecting the candidate sequence leading to a highest score or a lowest penalty as corresponding to the correct sequence for the one or more sample nucleic acids in the defined space.
Abstract:
The identification of mutations that are present in a small fraction of DNA templates is essential for progress in several areas of biomedical research. Though massively parallel sequencing instruments are in principle well-suited to this task, the error rates in such instruments are generally too high to allow confident identification of rare variants. We here describe an approach that can substantially increase the sensitivity of massively parallel sequencing instruments for this purpose. One example of this approach, called "Safe-SeqS" for (Safe-Sequencing System) includes (i) assignment of a unique identifier (UID) to each template molecule; (ii) amplification of each uniquely tagged template molecule to create UID-families; and (iii) redundant sequencing of the amplification products. PCR fragments with the same UID are truly mutant ("super-mutants") if =95% of them contain the identical mutation. We illustrate the utility of this approach for determining the fidelity of a polymerase, the accuracy of oligonucleotides synthesized in vitro, and the prevalence of mutations in the nuclear and mitochondrial genomes of normal cells.
Abstract:
The invention relates to a method for the detection of a target nucleotide sequence in a sample based on an oligonucleotide ligation assay wherein probes are used that contain (a combination of) sequence-based identifiers that can identify the sample and the target sequence (i.e. locus and/or allele combination) wherein after the ligation step, the ligated probes, or after amplification, the amplified ligated probes, are restricted using restriction enzymes to cut of part of the probes and continue with those parts (identifiers and target sequence) that contain the relevant information in the sequencing step.
Abstract:
Provided are methods for high-throughput screening to determine locations of double-stranded DNA breaks (DSBs) and translocations in genomes caused by different agents, such as enzymes.
Abstract:
The present invention provides a method capable of detecting single or multiple fetal chromosomal aneuploidies in a maternal sample comprising fetal and maternal nucleic acids, and verifying that the correct determination has been made. The method is applicable to determining copy number variations (CNV) of any sequence of interest in samples comprising mixtures of genomic nucleic acids derived from two different genomes, and which are known or are suspected to differ in the amount of one or more sequence of interest. The method is applicable at least to the practice of noninvasive prenatal diagnostics, and to the diagnosis and monitoring of conditions associated with a difference in sequence representation in healthy versus diseased individuals.