The present invention discloses a sequencing library comprising a nucleotide sequence. The sequence comprises a linker sequence and two target sequences. Two ends of the linker sequence are respectively linked to the target sequences and the two target sequences are direct repeat sequences. The present invention further discloses preparation and use of the sequencing library. The present invention overcomes the high error rate problem of current DNA sequencing technologies, especially in a way of very low coverage bias, and can be used to detect low frequency mutations in different kinds of samples.

The present invention discloses a sequencing library comprising a nucleotide sequence. The sequence comprises a linker sequence and two target sequences. Two ends of the linker sequence are respectively linked to the target sequences and the two target sequences are direct repeat sequences. The present invention further discloses preparation and use of the sequencing library. The present invention overcomes the high error rate problem of current DNA sequencing technologies, especially in a way of very low coverage bias, and can be used to detect low frequency mutations in different kinds of samples.

Disclosed are systems and methods for detecting genetic alterations comprising androgen receptor gene splice variants (AR-Vs), mutations, indel, copy number changes, fusion and combination thereof, in a biofluid sample from the patient. The systems and methods are similarly applicable to the detection of gene alterations comprising gene splicing variants, mutations, indel, copy number changes, fusion and combination thereof of other genes of interest. The streamlined methods improve the consistency and simplicity of non-invasive detections of biomarkers.

Disclosed are systems and methods for detecting genetic alterations comprising androgen receptor gene splice variants (AR-Vs), mutations, indel, copy number changes, fusion and combination thereof, in a biofluid sample from the patient. The systems and methods are similarly applicable to the detection of gene alterations comprising gene splicing variants, mutations, indel, copy number changes, fusion and combination thereof of other genes of interest. The streamlined methods improve the consistency and simplicity of non-invasive detections of biomarkers.

Methods and systems for decreasing amplification bias and primer-dimer formation in amplification reactions and for amplifying a plurality of target polynucleotides from a sample in a single reaction and for sequencing the target polynucleotides where samples can include forensic samples and where target polynucleotides can include identity- or ancestry-informative markers, short tandem repeats (STRs) and single nucleotide polymorphisms (SNPs). Methods of determining a nucleotide spacer sequence for disrupting primer dimer formation can include: receiving a set of primer sequences; determining a plurality of candidate spacers between an adapter sequence and a gene-specific portion of the primer sequence, the determined plurality of candidate spacers comprises sequences that disrupt stable interactions between sequences of the set of primer sequences; ranking candidate spacers that meet a predetermined threshold value of stable interactions in the extension sequences; and outputting a set of the ranked spacers that meet the predetermined threshold.

Methods and systems for decreasing amplification bias and primer-dimer formation in amplification reactions and for amplifying a plurality of target polynucleotides from a sample in a single reaction and for sequencing the target polynucleotides where samples can include forensic samples and where target polynucleotides can include identity- or ancestry-informative markers, short tandem repeats (STRs) and single nucleotide polymorphisms (SNPs). Methods of determining a nucleotide spacer sequence for disrupting primer dimer formation can include: receiving a set of primer sequences; determining a plurality of candidate spacers between an adapter sequence and a gene-specific portion of the primer sequence, the determined plurality of candidate spacers comprises sequences that disrupt stable interactions between sequences of the set of primer sequences; ranking candidate spacers that meet a predetermined threshold value of stable interactions in the extension sequences; and outputting a set of the ranked spacers that meet the predetermined threshold.

The present invention relates to the analysis of complex single cell sequencing libraries. Disclosed are methods for enrichment of library members based on the presence of cell-of origin barcodes to identify and concentrate DNA that is relevant to interesting cells or components that would be expensive or difficult to study otherwise. Also, disclosed are methods of capturing cDNA library molecules by use of CRISPR systems, hybridization or PCR. The present invention allows for identifying the properties of rare cells in single cell RNA-seq data and accurately profile them through clustering approaches. Further information on transcript abundances from subpopulations of single cells can be analyzed at a lower sequencing effort. The methods also allow for linking TCR alpha and beta chains at the single cell level.

The present invention relates to the analysis of complex single cell sequencing libraries. Disclosed are methods for enrichment of library members based on the presence of cell-of origin barcodes to identify and concentrate DNA that is relevant to interesting cells or components that would be expensive or difficult to study otherwise. Also, disclosed are methods of capturing cDNA library molecules by use of CRISPR systems, hybridization or PCR. The present invention allows for identifying the properties of rare cells in single cell RNA-seq data and accurately profile them through clustering approaches. Further information on transcript abundances from subpopulations of single cells can be analyzed at a lower sequencing effort. The methods also allow for linking TCR alpha and beta chains at the single cell level.

Embodiments of a method and/or system can include generating a set of quality control template (QCT) molecules; determining a set of QCT sequence read clusters based on the set of QCT molecules, such as based on variation regions of the set of QCT molecules; and based on the set of QCT sequence read clusters, determining a sequencing-related parameter, such as a contamination parameter and/or molecule count parameter, associated with the at least one of sequencing library preparation and sequencing.

The present disclosure provides methods and kits for tracking nucleic acid target origin by barcode tagging of the targets when they break into smaller fragments. Nucleic acid targets are captured in vitro by clonally localized nucleic acid barcode templates on a solid support. Millions of nucleic acid targets can be processed simultaneously in a massively parallel fashion without additional partition. These captured targets are broken into small fragments, and a target specific barcode sequence is tagged on each fragment as an identification of their original target. These nucleic acid target tracking methods can be used for a variety of applications in both whole genome sequencing and targeted sequencing.