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 blocking the 3′ ends of pooled indexed polynucleotides from multiple samples prior to amplification and sequencing, by exonuclease treatment and optionally blocking the 3′ ends of pooled indexed polynucleotides from multiple samples prior to amplification and sequencing, by exonuclease treatment after protective adapters are ligated to target polynucleotides to degrade unincorporated adapters prior to amplification and sequencing, and/or by modifying or blocking 5′ and 3′ ends of pooled indexed polynucleotides from multiple samples, with an optional exonuclease treatment, prior to amplification and sequencing.

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 modifying or blocking 5′ and 3′ ends of pooled indexed polynucleotides from multiple samples, with an optional exonuclease treatment, prior to amplification and sequencing.

The present disclosure provides methods and systems for generation of compositions comprising two or more sets of molecules. Compositions herein may comprise sets of molecules of different types. Sets of molecules may be generated by attachment to supports. Different types of molecules may be used to generate a large number of unique molecules. One or more types of molecules may be used to identify one or more additional types of molecules. Compositions of the present disclosure may be used in, for example, nucleic acid sequencing.

The invention is directed to methods for synthesizing oligonucleotides direction on biomolecules or cells living or fixed. In some embodiments, template-free enzymatic synthesis is implemented under biological conditions with successive cycles of (i) enzymatic addition of a 3′-O-blocked nucleoside triphosphate and (ii) enzymatic deblocking of the incorporated nucleotide to regenerate a free 3′ hydroxyl. The invention has applications in single-cell cDNA library construction and analysis.

Provided are methods and systems useful for screening large libraries of effector molecules. Such methods and systems are particularly useful in microfluidic systems and devices. The methods and systems provided herein utilize encoded effectors to screen large libraries of effectors.

Provided are methods and systems useful for screening large libraries of effector molecules. Such methods and systems are particularly useful in microfluidic systems and devices. The methods and systems provided herein utilize encoded effectors to screen large libraries of effectors.

The invention relates to the chemical synthesis of oligonucleotides, e.g., oligoribonucleotides. In another aspect, the invention relates to compounds of formula (II): ##STR00001##
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.

The invention relates to the chemical synthesis of oligonucleotides, e.g., oligoribonucleotides. In another aspect, the invention relates to compounds of formula (II): ##STR00001##
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.

Methods and compositions for preparing a nucleic acid sequencing library are described including (a)transposing an insertion sequence into first fragments of the target nucleic acid, wherein the insertion sequence comprises a hybridization sequence, and wherein the transposing produces nicks in the first fragments; (b) combining in a single mixture (i) the first fragments of the target nucleic acid from (a), (ii) a splint oligonucleotide, and (iii) a population of beads, wherein each bead comprises capture oligonucleotides immobilized thereon, and (c) ligating capture oligonucleotides of individual beads to inserted hybridization sequences of individual first fragments.

Methods and compositions for preparing a nucleic acid sequencing library are described including (a)transposing an insertion sequence into first fragments of the target nucleic acid, wherein the insertion sequence comprises a hybridization sequence, and wherein the transposing produces nicks in the first fragments; (b) combining in a single mixture (i) the first fragments of the target nucleic acid from (a), (ii) a splint oligonucleotide, and (iii) a population of beads, wherein each bead comprises capture oligonucleotides immobilized thereon, and (c) ligating capture oligonucleotides of individual beads to inserted hybridization sequences of individual first fragments.