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.

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 provides a computer-implemented method for detecting variant nucleic acid from a cell-free nucleic acid-containing sample. The method comprises (a) providing data representing fragment sizes of nucleic acid fragments obtained from said sample and/or representing a measure of deviation from copy number neutrality of the nucleic acid fragments obtained from said sample; b) processing the data from step a) according to a classification algorithm, wherein said classification algorithm operates to classify sample data into one of at least a first class containing the variant nucleic acid and a second class not containing the variant nucleic acid, based on a plurality of cell-free nucleic acid fragment size features and/or a deviation from copy number neutrality feature; and c) outputting the classification of the sample from step b, thereby determining whether the sample contains the variant nucleic acid or not, or a probability that the sample contains the variant nucleic acid. Related methods are also provided.

Described herein are methods and vectors for rational, multiplexed manipulation of chromosomes within open reading frames (e.g., in protein libraries) or any segment of a chromosome in a cell or population of cells, in which various CRISPR systems are used.

Disclosed herein are methods and compositions for generating a repertoire of recombinant fusion polypeptides from immune cells, and uses thereof.

Provided herein are compositions and methods for accurate and scalable Primary Template-Directed Amplification (PTA) nucleic acid amplification and sequencing methods, and their applications for mutational analysis in research, diagnostics, and treatment. Further provided herein are multiomics methods for parallel analysis of DNA, RNA, and/or proteins from single cells. Provided herein are methods of multiomic single-cell analysis comprising: (a) isolating a single cell from a population of cells; (b) sequencing a cDNA library comprising polynucleotides amplified from mRNA transcripts from the single cell; and (c) sequencing a genome of the single cell.

Provided herein are compositions and methods for accurate and scalable Primary Template-Directed Amplification (PTA) nucleic acid amplification and sequencing methods, and their applications for mutational analysis in research, diagnostics, and treatment. Further provided herein are multiomics methods for parallel analysis of DNA, RNA, and/or proteins from single cells. Provided herein are methods of multiomic single-cell analysis comprising: (a) isolating a single cell from a population of cells; (b) sequencing a cDNA library comprising polynucleotides amplified from mRNA transcripts from the single cell; and (c) sequencing a genome of the single cell.

The present disclosure relates to methods for enriching circulating tumor DNA (ctDNA) to enhance early disease detection or predictions of disease progression. The present disclosure also relates to methods for enriching circulating fetal cell free DNA (fetal cfDNA) to enhance early disease detection. In some embodiments, the method comprises enriching ctDNA or fetal cfDNA in a sample by selecting for cell-free nucleic acid fragments that are less than 150 bp prior to copy number alteration (CNA) analysis. Also disclosed are compositions, systems, and computer-program products for analyzing circulating cell free nucleic acids by any of the methods disclosed herein.

The present disclosure relates to methods for enriching circulating tumor DNA (ctDNA) to enhance early disease detection or predictions of disease progression. The present disclosure also relates to methods for enriching circulating fetal cell free DNA (fetal cfDNA) to enhance early disease detection. In some embodiments, the method comprises enriching ctDNA or fetal cfDNA in a sample by selecting for cell-free nucleic acid fragments that are less than 150 bp prior to copy number alteration (CNA) analysis. Also disclosed are compositions, systems, and computer-program products for analyzing circulating cell free nucleic acids by any of the methods disclosed herein.

It is provided the synthesis of an aptamer-like encoded oligomer (ALEnOmer), method of producing same and method of preparing a library of ALEnOmes. More particularly, the method of preparing ALEnOmer comprises coupling at least one phosphoramidite monomer with an orthogonal protecting group, and the ALEnOmer produces comprises a DNA coding strand covalently attached to an oligomer through a branching unit, wherein the oligomer has a degree of polymerization at least 5 and is an aptamer.