Abstract: The present disclosure provides compositions and methods for using fixed biological samples in partition-based assays. In at least one embodiment, the disclosure provides a composition comprising a fixed biological sample and an un-fixing agent contained in a partition, such as a discrete droplet. In some embodiments, the disclosure provides un-fixing agent compounds capable of catalytically cleaving crosslinks in fixed biological samples, particularly crosslinked nucleic acids, such as RNA.

Abstract: The present disclosure relates in some aspects to methods and compositions for in situ analysis involving catalytic de-crosslinking of biological samples.

Abstract: This disclosure relates to compositions and methods for three-dimensional spatial profiling of analytes in a biological sample. The methods include use of a hydrogel comprising one or more polymers that include a phenol moiety, an azide moiety, or an alkyne moiety.

Abstract: The present disclosure relates in some aspects to methods and compositions for in situ analysis involving catalytic de-crosslinking of biological samples.

Abstract: The present disclosure provides systems and methods for making a hydrogel comprising a cell, cell nucleus, or one or more components derived from a cell or cell nucleus. A method for making a hydrogel may comprise providing a cell or cell nucleus, a first polymer, wherein the first polymer comprises a plurality of first crosslink precursors, each of the plurality of first crosslink precursors comprising an azide group; providing a second polymer, wherein the second polymer comprises a plurality of second crosslink precursors, each of the plurality of second crosslink precursors comprising an alkyne group; and crosslinking the first polymer and the second polymer via a reaction between a first section of the first crosslink precursors and a second section of the second crosslink precursors, thereby providing the hydrogel comprising the cell or cell nucleus.

Abstract: The present disclosure relates generally to compositions and methods for generating hydrogel coatings on features. In some embodiments, hydrogel-coated features are prepared by horseradish peroxidase-mediated gelation of microspheres. Some embodiments relate to methods for generating hydrogel coatings using particle templated emulsification. The disclosure also relates to the use of hydrogel-coated features in arrays for spatial analysis of biological analytes in biological samples.

Abstract: The present disclosure provides methods, compositions, and systems for selective enzymatic gelation of cells, e.g., immune cells, contained in partitions.

Abstract: The present disclosure provides compositions, methods, and kits comprising a nano-partition contained within a partition that allows for the separation and use of at least two enzymes in a partition-based assay of a biological sample, such as a single cell in a droplet. The compositions and methods are useful for carrying out partition-based assays of fixed biological samples.

Abstract: The present disclosure provides systems and methods for making a hydrogel comprising a cell, cell nucleus, or one or more components derived from a cell or cell nucleus. A method for making a hydrogel may comprise providing a cell or cell nucleus, a first polymer, wherein the first polymer comprises a plurality of first crosslink precursors, each of the plurality of first crosslink precursors comprising an azide group; providing a second polymer, wherein the second polymer comprises a plurality of second crosslink precursors, each of the plurality of second crosslink precursors comprising an alkyne group; and crosslinking the first polymer and the second polymer via a reaction between a first section of the first crosslink precursors and a second section of the second crosslink precursors, thereby providing the hydrogel comprising the cell or cell nucleus.

Abstract: The present disclosure relates to compositions and methods for reversible fixation of biological samples using fixation reagents that form bis-carbamate crosslinks between amine-bearing moieties in biomolecules.

Abstract: The present disclosure provides systems and methods for making a hydrogel comprising a cell, cell nucleus, or one or more components derived from a cell or cell nucleus. A method for making a hydrogel may comprise providing a cell or cell nucleus, a first polymer, wherein the first polymer comprises a plurality of first crosslink precursors, each of the plurality of first crosslink precursors comprising an azide group; providing a second polymer, wherein the second polymer comprises a plurality of second crosslink precursors, each of the plurality of second crosslink precursors comprising an alkyne group; and crosslinking the first polymer and the second polymer via a reaction between a first section of the first crosslink precursors and a second section of the second crosslink precursors, thereby providing the hydrogel comprising the cell or cell nucleus.

Abstract: Provided herein are methods of determining a location of a biological analyte in a biological sample.

Abstract: The present disclosure provides compositions and methods for using fixed biological samples in partition-based assays. In at least one embodiment, the disclosure provides a composition comprising a fixed biological sample and an un-fixing agent contained in a partition, such as a discrete droplet. In some embodiments, the disclosure provides un-fixing agent compounds capable of catalytically cleaving crosslinks in fixed biological samples, particularly crosslinked nucleic acids, such as RNA.

Abstract: The present disclosure provides systems and methods for making a hydrogel comprising a cell, cell nucleus, or one or more components derived from a cell or cell nucleus. A method for making a hydrogel may comprise providing a cell or cell nucleus, a first polymer, wherein the first polymer comprises a plurality of first crosslink precursors, each of the plurality of first crosslink precursors comprising an azide group; providing a second polymer, wherein the second polymer comprises a plurality of second crosslink precursors, each of the plurality of second crosslink precursors comprising an alkyne group; and crosslinking the first polymer and the second polymer via a reaction between a first section of the first crosslink precursors and a second section of the second crosslink precursors, thereby providing the hydrogel comprising the cell or cell nucleus.

Abstract: The present disclosure provides systems and methods for making a hydrogel comprising a cell, cell nucleus, or one or more components derived from a cell or cell nucleus. A method for making a hydrogel may comprise providing a cell or cell nucleus, a first polymer, wherein the first polymer comprises a plurality of first crosslink precursors, each of the plurality of first crosslink precursors comprising an azide group; providing a second polymer, wherein the second polymer comprises a plurality of second crosslink precursors, each of the plurality of second crosslink precursors comprising an alkyne group; and crosslinking the first polymer and the second polymer via a reaction between a first section of the first crosslink precursors and a second section of the second crosslink precursors, thereby providing the hydrogel comprising the cell or cell nucleus.

Abstract: The present disclosure provides systems and methods for making a hydrogel comprising a cell, cell nucleus, or one or more components derived from a cell or cell nucleus. A method for making a hydrogel may comprise providing a cell or cell nucleus, a first polymer, wherein the first polymer comprises a plurality of first crosslink precursors, each of the plurality of first crosslink precursors comprising an azide group; providing a second polymer, wherein the second polymer comprises a plurality of second crosslink precursors, each of the plurality of second crosslink precursors comprising an alkyne group; and crosslinking the first polymer and the second polymer via a reaction between a first section of the first crosslink precursors and a second section of the second crosslink precursors, thereby providing the hydrogel comprising the cell or cell nucleus.

Abstract: The present disclosure provides systems and methods for making a hydrogel comprising a cell, cell nucleus, or one or more components derived from a cell or cell nucleus. A method for making a hydrogel may comprise providing a cell or cell nucleus, a first polymer, wherein the first polymer comprises a plurality of first crosslink precursors, each of the plurality of first crosslink precursors comprising an azide group; providing a second polymer, wherein the second polymer comprises a plurality of second crosslink precursors, each of the plurality of second crosslink precursors comprising an alkyne group; and crosslinking the first polymer and the second polymer via a reaction between a first section of the first crosslink precursors and a second section of the second crosslink precursors, thereby providing the hydrogel comprising the cell or cell nucleus.

Abstract: The present disclosure provides systems and methods for making a hydrogel comprising a cell, cell nucleus, or one or more components derived from a cell or cell nucleus. A method for making a hydrogel may comprise providing a cell or cell nucleus, a first polymer, wherein the first polymer comprises a plurality of first crosslink precursors, each of the plurality of first crosslink precursors comprising an azide group; providing a second polymer, wherein the second polymer comprises a plurality of second crosslink precursors, each of the plurality of second crosslink precursors comprising an alkyne group; and crosslinking the first polymer and the second polymer via a reaction between a first section of the first crosslink precursors and a second section of the second crosslink precursors, thereby providing the hydrogel comprising the cell or cell nucleus.

Abstract: The present disclosure provides systems and methods for making a hydrogel comprising a cell, cell nucleus, or one or more components derived from a cell or cell nucleus. A method for making a hydrogel may comprise providing a cell or cell nucleus, a first polymer, wherein the first polymer comprises a plurality of first crosslink precursors, each of the plurality of first crosslink precursors comprising an azide group; providing a second polymer, wherein the second polymer comprises a plurality of second crosslink precursors, each of the plurality of second crosslink precursors comprising an alkyne group; and crosslinking the first polymer and the second polymer via a reaction between a first section of the first crosslink precursors and a second section of the second crosslink precursors, thereby providing the hydrogel comprising the cell or cell nucleus.