Disclosed herein is a method for providing a preparation for detecting a target nucleic acid sequence in a specimen. According to an embodiment, conventional nucleic acid extraction processes performed in many steps can be omitted, whereby the shortage of nucleic acid extraction reagents can be solved and a preparation for detecting target nucleic acid sequence in a specimen can be supplied in an inexpensive and simple manner.

Disclosed herein are methods for the detection of the presence of sperm DNA fragmentation in a semen sample. The methods include embedding of sperm cells of the semen sample in a gel, denaturing DNA of the sperm cells, and lysing the nuclear proteins of the sperm cells. The present method includes an ionic surfactant sodium dodycyl sulfate (SDS) and a chaotropic agent urea in the lysis solution for releasing DNA from protamine of chromosome, which significantly reduces the time required for lysis. A kit for detecting sperm DNA fragmentation in a semen sample is also disclosed.

Disclosed herein are methods for the detection of the presence of sperm DNA fragmentation in a semen sample. The methods include embedding of sperm cells of the semen sample in a gel, denaturing DNA of the sperm cells, and lysing the nuclear proteins of the sperm cells. The present method includes an ionic surfactant sodium dodycyl sulfate (SDS) and a chaotropic agent urea in the lysis solution for releasing DNA from protamine of chromosome, which significantly reduces the time required for lysis. A kit for detecting sperm DNA fragmentation in a semen sample is also disclosed.

The present disclosure provides methods for determining the ploidy status of a chromosome in a gestating fetus from genotypic data measured from a mixed sample of DNA comprising DNA from both the mother of the fetus and from the fetus, and optionally from genotypic data from the mother and father. The ploidy state is determined by using a joint distribution model to create a plurality of expected allele distributions for different possible fetal ploidy states given the parental genotypic data, and comparing the expected allelic distributions to the pattern of measured allelic distributions measured in the mixed sample, and choosing the ploidy state whose expected allelic distribution pattern most closely matches the observed allelic distribution pattern. The mixed sample of DNA may be preferentially enriched at a plurality of polymorphic loci in a way that minimizes the allelic bias, for example using massively multiplexed targeted PCR.

A gene sequencing reaction device, a gene sequencing system and a gene sequencing reaction method. The gene sequencing reaction device includes: a supporting platform; a dipping container disposed on the supporting platform, wherein the dipping container has a dipping reaction area, and the dipping reaction area is configured to hold a chemical reagent for gene sequencing reaction, so as to dip a sequencing chip having a DNA sample loading structure on the surface and having a DNA sample loaded thereon in the chemical reagent to perform a gene sequencing reaction; a temperature control apparatus, configured to control the temperature of the chemical reagent in the dipping reaction area; and a transfer apparatus, configured to insert the sequencing chip into the dipping reaction area or pull out the sequencing chip from the dipping reaction area.

A gene sequencing reaction device, a gene sequencing system and a gene sequencing reaction method. The gene sequencing reaction device includes: a supporting platform; a dipping container disposed on the supporting platform, wherein the dipping container has a dipping reaction area, and the dipping reaction area is configured to hold a chemical reagent for gene sequencing reaction, so as to dip a sequencing chip having a DNA sample loading structure on the surface and having a DNA sample loaded thereon in the chemical reagent to perform a gene sequencing reaction; a temperature control apparatus, configured to control the temperature of the chemical reagent in the dipping reaction area; and a transfer apparatus, configured to insert the sequencing chip into the dipping reaction area or pull out the sequencing chip from the dipping reaction area.

The present disclosure provides methods for determining the ploidy status of a chromosome in a gestating fetus from genotypic data measured from a mixed sample of DNA comprising DNA from both the mother of the fetus and from the fetus, and optionally from genotypic data from the mother and father. The ploidy state is determined by using a joint distribution model to create a plurality of expected allele distributions for different possible fetal ploidy states given the parental genotypic data, and comparing the expected allelic distributions to the pattern of measured allelic distributions measured in the mixed sample, and choosing the ploidy state whose expected allelic distribution pattern most closely matches the observed allelic distribution pattern. The mixed sample of DNA may be preferentially enriched at a plurality of polymorphic loci in a way that minimizes the allelic bias, for example using massively multiplexed targeted PCR.

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, 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.

A method for identifying a nucleic acid template that includes (a) providing a plurality of primer-template hybrids, wherein a first hybrid of the plurality includes a first template hybridized to a first primer, and wherein a second hybrid of the plurality includes a second template hybridized to a second primer, the second primer having a ternary complex inhibitor moiety at the 3′ end; (b) delivering polymerases and nucleotides to the plurality, whereby the first hybrid binds a polymerase and nucleotide to form a stabilized ternary complex and whereby the second hybrid does not bind a polymerase and nucleotide to form a stabilized ternary complex; and (c) detecting the stabilized ternary complex to identify the first template.