Provided herein are compositions and methods to identify a binding element (e.g., peptide, peptoid, or protein) that can be bound by an immunoreceptor (e.g., antibody). The binding element can be provided in a target binding unit comprising two binding elements separated by a spacer such that the two binding elements simultaneously bind to a single molecule comprising an antigen binding domain of an antibody. The present disclosure provides various methods to construct the spacer. The identified binding elements can be further used to manufacture an array which can be used to profile antibodies obtained from a blood sample.

Selectively controllable cleavable linkers include electrochemically-cleavable linkers, photolabile linkers, thermolabile linkers, chemically-labile linkers, and enzymatically-cleavable linkers. Selective cleavage of individual linkers may be controlled by changing local conditions. Local conditions may be changed by activating electrodes in proximity to the linkers, exposing the linkers to light, heating the linkers, or applying chemicals. Selective cleaving of enzymatically-cleavable linkers may be controlled by designing the sequences of different sets of the individual linkers to respond to different enzymes. Cleavable linkers may be used to attach polymers to a solid substrate. Selective cleavage of the linkers enables release of specific polymers from the solid substrate. Cleavable linkers may also be used to attach protecting groups to the ends of growing polymers. The protecting groups may be selectively removed by cleavage of the linkers to enable growth of specific polymers.

The present invention is concerned with compositions and methods for improving the rate of correct sample identification in indexed nucleic acid library preparations for multiplex next generation sequencing by exonuclease treatment and optionally blocking the 3′ ends of pooled indexed polynucleotides from multiple samples prior to amplification and sequencing.

The present technology provides an approach to designing libraries of peptide sequences for discovery and testing of significantly more motifs than would be otherwise available in a given fixed library format. The technology includes a plurality of x-mers embedded in N-mer peptides sequences, where N and x are integers and where N is greater than x. This approach provides for the representation of multiple unique x-mer peptides in a single N-mer peptide feature.

The present technology provides an approach to designing libraries of peptide sequences for discovery and testing of significantly more motifs than would be otherwise available in a given fixed library format. The technology includes a plurality of x-mers embedded in N-mer peptides sequences, where N and x are integers and where N is greater than x. This approach provides for the representation of multiple unique x-mer peptides in a single N-mer peptide feature.

Methods for preparing sequencing libraries from a DNA-containing test sample, as well as methods for correcting sequencing-derived errors, are provided.

Systems, methods, and compositions provided herein relate to preparation of beads encapsulating biomolecules for performing sequential reactions on the biomolecules. Some embodiments include preparation of nucleic acid reactions within the bead, wherein the bead includes pores that allow diffusion of molecules into or out of the beads while retaining other molecules of interest.

Systems, methods, and compositions provided herein relate to preparation of beads encapsulating biomolecules for performing sequential reactions on the biomolecules. Some embodiments include preparation of nucleic acid reactions within the bead, wherein the bead includes pores that allow diffusion of molecules into or out of the beads while retaining other molecules of interest.

A composition and method for controlled in vitro fragmentation of nucleic acids. A transposase forms catalytically active complexes with a modified transposon end that contains within its end sequence degenerate, apurinic/apyrimidinic sites, nicks, or nucleotide gaps, to fragment or shear a target nucleic acid sample in a controlled process. This method yields desired average nucleic acid fragment sizes. The inventive composition and method may be applied for generation of DNA fragments containing shortened transposon end sequences to facilitate subsequent reactions, for production of asymmetrically tailed DNA fragments, etc.

The invention relates to the chemical synthesis of oligonucleotides, e.g., oligoribonucleotides. In another aspect, the invention relates to compounds of formula (II):

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processes for making these compounds, and the use thereof in the chemical synthesis of oligonucleotides, e.g., oligoribonucleotides. The invention also relates to methods of synthesis of oligomers, including but not limited to oligopeptides, oligosaccharides and oligonucleotides, particularly oligoribonucleotides and also oligodeoxyribonucleotides, in solution systems, and ionic tag linkers for use in methods provided herein.