Methods of generating a nucleic acid signature for identifying particles associated in a partition are provided. In one aspect, the method comprises: partitioning a sample into a plurality of partitions comprising a particle comprising a solid support surface, the solid support surface having a plurality of oligonucleotide primers conjugated thereon, wherein the oligonucleotide primers comprise a barcode sequence, and wherein the partitions have 0, 1, or more than 1 particles per partition; providing in a partition a substrate comprising a barcode sequence or repeating clonal barcode sequences; and in the partition, associating a first particle conjugated to oligonucleotide primers comprising a first barcode sequence and a second particle conjugated to oligonucleotide primers comprising a second barcode sequence to a barcode sequence from the substrate, thereby generating a nucleic acid signature for the particles in the partition.

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.

Embodiments disclosed herein are directed to microfluidic devices that allow for scalable on-chip screening of combinatorial libraries and methods of use thereof. Droplets comprising individual molecular species to be screened are loaded onto the microfluidic device. The droplets are labeled by methods known in the art, including but not limited to barcoding, such that the molecular species in each droplet can be uniquely identified. The device randomly sorts the droplets into individual microwells of an array of microwells designed to hold a certain number of individual droplets in order to derive combinations of the various molecular species. The paired droplets are then merged in parallel to form merged droplets in each microwell, thereby avoiding issues associated with single stream merging. Each microwell is then scanned, e.g., using microscopy, such as high content imaging microscopy, to detect the optical labels, thereby identifying the combination of molecular species in each microwell.

This disclosure describes compositions, methods, and systems for constructing defined variation in a contiguous functional genetic unit in association with a unique sequence identifier (“a barcode”) in a combinatorial manner.

Embodiments disclosed herein are directed to microfluidic devices that allow for scalable on-chip screening of combinatorial libraries and methods of use thereof. Droplets comprising individual molecular species to be screened are loaded onto the microfluidic device. The droplets are labeled by methods known in the art, including but not limited to barcoding, such that the molecular species in each droplet can be uniquely identified. The device randomly sorts the droplets into individual microwells of an array of microwells designed to hold a certain number of individual droplets in order to derive combinations of the various molecular species. The paired droplets are then merged in parallel to form merged droplets in each microwell, thereby avoiding issues associated with single stream merging. Each microwell is then scanned, e.g., using microscopy, such as high content imaging microscopy, to detect the optical labels, thereby identifying the combination of molecular species in each microwell.

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.

A fluid transfer system includes a transfer carousel capable of rotational and/or translational movement; at least one holding vessel (e.g. syringe) having a plunger, wherein the syringe is connected to the transfer carousel such that the movement of the transfer carousel results in movement of the syringe and wherein the syringe is capable of translational movement relative to the transfer carousel; a drive motor connected to the syringe that is capable of controlling the position of the plunger; and a peripheral module comprising at least one vessel that is capable of containing a fluid, wherein the vessel has an opening that can be mated with the syringe to allow fluid transfer between the vessel and the syringe. Methods for transferring a fluid are also disclosed.

The present disclosure provides particles (e.g., beads) and methods, kits, and systems involving the same for sample processing or analysis. Such particles may include one or more analytes, one or more reagents, and two or more gel components and/or walled components. The particles described herein may be formed, for example, by polymerization of a polymerizable material in proximity to a gel or walled component.

A microarray assembly for detection of a target molecule is disclosed. The microarray assemblies comprise an array chamber having a microarray located therein and features that facilitate liquid movement within the array chamber. Also disclosed are methods for making the microarray assembly using rollable films and methods for detecting microarray spots using an internal control fluorophore in the array spot.