The invention is a novel method of separately sequencing each strand of a nucleic acid involving the use of an adaptor comprising a strand cleavage site or a strand synthesis termination site. The adaptor may also be self-priming at the strand cleavage site.

Provided is a method for replicating a mirror nucleic acid, comprising: reacting a mirror nucleic acid template, a mirror nucleic acid primer and mirror dNTPs/rNTPs in the presence of a mirror nucleic acid polymerase, so as to obtain the mirror nucleic acid.

Methods and systems for sample preparation techniques that allow amplification (e.g., whole genome amplification) and sequencing of chromatin accessible regions of single cells are provided. The methods and systems generally operate by forming or providing partitions (e.g., droplets) including a single biological particle and a single bead comprising a barcoded oligonucleotide. The preparation of barcoded next-generation sequencing libraries prepared from a single cell is facilitated by the transposon-mediated transposition and fragmentation of a target nucleic acid sequence. The methods and systems may be configured to allow the implementation of single-operation or multi-operation chemical and/or biochemical processing within the partitions.

This application provides a bead with a covalently attached chemical compound and a covalently attached DNA barcode and methods for using such beads. The bead has many substantially identical copies of the chemical compound and many substantially identical copies of the DNA barcode. The compound consists of one or more chemical monomers, where the DNA barcode takes the form of barcode modules, where each module corresponds to and allows identification of a corresponding chemical monomer. The nucleic acid barcode can have a concatenated structure or an orthogonal structure. Provided are method for sequencing the bead-bound nucleic acid barcode, for cleaving the compound from the bead, and for assessing biological activity of the released compound.

Presented herein are transposase enzymes and reaction conditions for improved fragmentation and tagging of nucleic acid samples, in particular altered transposases and reaction conditions which exhibit improved insertion sequence bias, as well as methods and kits using the same.

The present invention provides methods for generating a library of synthetic polynucleotides. The present invention also provides methods for generating proteins encoded by the library of synthetic polynucleotides. In addition, provided herein are methods for determining the soluble expression of said proteins. This invention is based, in part, on the discovery of a method for selecting optimal oligonucleotides in combination with performing a phosphorylation reaction, ligation reaction and PCR amplification in a single reaction vessel to produce synthetic polynucleotides in a multiplex manner.

A parallelized chain-synthesizing technique includes capillary tubes, where each tube provides multiple locations or addresses where a specific arbitrary sequence for polymeric chains can be synthesized. An optical addressing system selectively delivers light to the locations to mediate or control reactions in the tubes.

A method and reagent for constructing a nucleic acid double-linker single-strand cyclic library. The method comprises: breaking a nucleic acid into nucleic acid fragments; connecting a first linker sequence; producing by amplification a first product provided with the first linker sequence at either end, where a U nucleobase site is provided on primer sequences and a nicking enzyme recognition sequence is either provided or not provided on same, and a first affinity tag is provided on one of the primer sequences; using USER enzyme to cleave the first product; cyclizing the cleaved first product; treating the cyclization product with either a phosphatase or a nicking enzyme; using a solid-phase vector for combination with a cyclized molecule; performing a restrictive gap translation reaction; removing by digestion any portion that did not undergo the restrictive gap translation reaction; connecting a second linker sequence; producing by amplification a second product provided with the second linker sequence at either end; denaturing the second product, and cyclizing a single-strand nucleic acid molecule. The method allows an increase in the length of library insert fragments, a simplified library construction process, reduced library construction time, and reduced library construction costs.

The present invention relates to a method for the highly specific, targeted capture of regions of human genomes and transcriptomes from the blood, i.e. from cell free circulating DNA, exosomes, microRNA, circulating tumor cells, or total blood cells, to allow for the highly sensitive detection of mutation, expression, copy number, translocation, alternative splicing, and methylation changes using combined nuclease, ligation, polymerase, and massively parallel sequencing reactions. The method generates a collection of different circular chimeric single-stranded nucleic acid constructs, suitable for sequencing on multiple platforms. In some embodiments, each construct of the collection comprised a first single stranded segment of original genomic DNA from a host organism and a second single stranded synthetic nucleic acid segment that is linked to the first single stranded segment and comprises a nucleotide sequence that is exogenous to the host organism. These chimeric constructs are suitable for identifying and enumerating mutations, copy changes, translocations, and methylation changes. In other embodiments, input mRNA, lncRNA, or miRNA is used to generate circular DNA products that reflect the presence and copy number of specific mRNA's, lncRNA's splice-site variants, translocations, and miRNA.

Disclosed herein is an efficient method of generating a library of variants of a sequence of interest, such as may be used in directed evolution, in one embodiment, the method includes an amplification reaction, e.g. error-prone PCR, to generate double-stranded DNA (dsDNA) variants of a sequence of interest, after which one strand of the dsDNA variants may be selectively degraded to produce single-stranded DNA (ssDNA) variants. The ssDNA variants may be hybridized to ssDNA intermediaries, e.g., uracilated circular ssDNA intermediaries, to form heteroduplex DNA, which may be transformed into cells, such as E. coli cells, yielding a library of variants. This method eliminates the inefficient sub-cloning steps and the need for costly primer sets required by many prior methods.