The present disclosure provides methods and systems for sample preparation and/or analysis. Samples may be cells, or may be derived from one or more cells. Sample preparation may comprise conducting one or more reactions on a target. Such reactions may be conducted in one or more partitions. One or more reactions may be performed in one or more successive operations.

The present disclosure provides methods, systems, and kits for processing nucleic acid molecules. A method may comprise providing a template nucleic acid fragment (e.g., within a cell, cell bead, or cell nucleus) within a partition (e.g., a droplet or well) and subjecting the template nucleic acid fragment to one or more processes including a barcoding process and a single primer extension or amplification process. The processed template nucleic acid fragment may then be recovered from the partition and subjected to further amplification to provide material for subsequent sequencing analysis. The methods provided herein may permit simultaneous processing and analysis of both DNA and RNA molecules originating from the same cell, cell bead, or cell nucleus.

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.

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.

Digestible primers are incorporated into single cell analysis workflows to reduce and/or eliminate primer byproducts and misprimed nucleic acids. Specifically, digestible primers can participate in a first reaction, such as reverse transcription of RNA transcripts to generate cDNA, but digestible primers are digested to prevent them from participating in subsequent reactions, such as nucleic acid amplification. For example, digestible primers can include a primer with one or more ribonucleotide nucleobases, a primer with uracil bases, a primer with deoxyuridine sequences, or a primer with ribouridine sequences. Such primers can then be digested (e.g., enzymatically digested) to remove them from interfering in subsequent nucleic acid amplification reactions.

Digestible primers are incorporated into single cell analysis workflows to reduce and/or eliminate primer byproducts and misprimed nucleic acids. Specifically, digestible primers can participate in a first reaction, such as reverse transcription of RNA transcripts to generate cDNA, but digestible primers are digested to prevent them from participating in subsequent reactions, such as nucleic acid amplification. For example, digestible primers can include a primer with one or more ribonucleotide nucleobases, a primer with uracil bases, a primer with deoxyuridine sequences, or a primer with ribouridine sequences. Such primers can then be digested (e.g., enzymatically digested) to remove them from interfering in subsequent nucleic acid amplification reactions.

Provided herein are methods for generating single-cell molecular analysis comprising a) delivering one or more proximity dependent probes to a cell population, wherein each proximity dependent probe comprises a target binding region configured to bind a target RNA and a primer binding site region; b) linking bound proximity dependent probes; c) isolating single cells from the cell population in separate individual discrete volumes, the individual discrete volumes further comprising a primer pair and amplification reagents, wherein the primer pair binds to the primer binding sites of the ligation dependent probes, and wherein at least one primer comprises a barcode sequence that uniquely identifies the individual discrete volume; d) amplifying the ligated probes using the primer pair, wherein the barcode is incorporated into each resulting amplicon; and e) quantifying target RNAs in each individual cell based at least in part on sequencing the resulting amplicons.

The present disclosure provides a high-throughput screening system and method for identification of novel drugs and drug targets. The method enables large-scale analysis of interactions between allogeneic pairs of target cells and immune cells by using an immune-bridge protein, library of guide RNA, and/or 3D tumor model.

The present disclosure provides methods, compositions and systems for analyzing individual cells or cell populations through a partitioned analysis of contents of individual cells or cell populations, such as cancer cells and cells of the immune system. Individual cells or cell populations may be co-partitioned with processing reagents for accessing cellular contents, and for uniquely identifying the content of a given cell or cell population, and subsequently analyzing the content of the cell and characterizing it as having derived from an individual cell or cell population, including analysis and characterization of nucleic acid(s) from the cell through sequencing.

Provided is a method for screening an in vitro display library for binding within a cell of a small-molecule chemical compound binding entity of the library to a protein or RNA target of interest in order to identify at least one individual chemical compound binding entity of the library that is capable of binding within the cell to the protein or RNA target of interest.