Provided herein, among other things, are various compositions and methods for analyzing chromatin. In some embodiments, the composition may comprise a mixture of a nicking enzyme, four dNTPs, at least one labeled dNTP and, optionally, a polymerase. In some embodiments, this method may comprise: obtaining a sample comprising chromatin, reacting the sample with the composition to selectively label the open chromatin in the sample, and analyzing the labeled sample.

Provided herein, among other things, are various compositions and methods for analyzing chromatin. In some embodiments, the composition may comprise a mixture of a nicking enzyme, four dNTPs, at least one labeled dNTP and, optionally, a polymerase. In some embodiments, this method may comprise: obtaining a sample comprising chromatin, reacting the sample with the composition to selectively label the open chromatin in the sample, and analyzing the labeled sample.

The present invention generally relates to imaging cells, for example, to determine phenotypes and/or genotypes in populations of cells, e.g., to build genotype-phenotype corresponse for high-throughput screening. In some cases, the cells may be manipulated, e.g., using CRISPR or other techniques. In certain embodiments, nucleic acids may be introduced to the cell, e.g., using a lentivirus. The nucleic acids may contain a guide portion comprising a DNA or RNA recognition sequence, a reporter portion, and an identification portion comprising one or more read sequences. The guide portion may be used to alter the phenotype of the cells, e.g., using a sequence, e.g., an sgRNA sequence, that can be targeted using CRISPR or other techniques, and in some cases, the phenotype of the cells may be determined using various imaging approaches. The identification portion may be determined using MERFISH or other suitable techniques. In addition, in some cases, association or colocalization between determination of the reporter and the read sequences may substantially improve decoding accuracy, e.g., due to lowered misidentification of background signals. Other aspects are generally directed to compositions or devices for use in such methods, kits for use in such methods, or the like.

The present invention generally relates to imaging cells, for example, to determine phenotypes and/or genotypes in populations of cells, e.g., to build genotype-phenotype corresponse for high-throughput screening. In some cases, the cells may be manipulated, e.g., using CRISPR or other techniques. In certain embodiments, nucleic acids may be introduced to the cell, e.g., using a lentivirus. The nucleic acids may contain a guide portion comprising a DNA or RNA recognition sequence, a reporter portion, and an identification portion comprising one or more read sequences. The guide portion may be used to alter the phenotype of the cells, e.g., using a sequence, e.g., an sgRNA sequence, that can be targeted using CRISPR or other techniques, and in some cases, the phenotype of the cells may be determined using various imaging approaches. The identification portion may be determined using MERFISH or other suitable techniques. In addition, in some cases, association or colocalization between determination of the reporter and the read sequences may substantially improve decoding accuracy, e.g., due to lowered misidentification of background signals. Other aspects are generally directed to compositions or devices for use in such methods, kits for use in such methods, or the like.

In some aspects, the present disclosure relates to methods for reducing the crowding of signals, for example optical crowding, that can occur when nucleic acids are detected in a sample in multiplex, which can make it difficult to resolve individual signals and can lead to a reduced dynamic range. In some aspects, the present disclosure relates to methods for reducing signal crowding in the detection of multiple target nucleic acid sequences in a sample, e.g., using hybridization probes, wherein signal crowding from said hybridization probes is reduced. The methods herein have particular applicability in the detection of barcode sequences by sequencing-by-hybridization (SBH) methods, including those relying on combinatorial labelling schemes and decoding of the barcodes by sequential cycles of decoding using hybridization probes. Also provided are kits comprising probes for use in such methods.

In some aspects, the present disclosure relates to methods for reducing the crowding of signals, for example optical crowding, that can occur when nucleic acids are detected in a sample in multiplex, which can make it difficult to resolve individual signals and can lead to a reduced dynamic range. In some aspects, the present disclosure relates to methods for reducing signal crowding in the detection of multiple target nucleic acid sequences in a sample, e.g., using hybridization probes, wherein signal crowding from said hybridization probes is reduced. The methods herein have particular applicability in the detection of barcode sequences by sequencing-by-hybridization (SBH) methods, including those relying on combinatorial labelling schemes and decoding of the barcodes by sequential cycles of decoding using hybridization probes. Also provided are kits comprising probes for use in such methods.

The present disclosure in some aspects relates to methods for assessing multi-modal in situ transcriptomics by combining microscopy and sequencing technologies and methods. In some aspects, the methods provided herein involve analyzing one or more analyte panels in a sample using a first imaging modality or set of imaging modalities. Based on said analysis, a different analyte panel and/or one or more different imaging modalities can be selected for subsequent analysis.

The present disclosure in some aspects relates to methods for assessing multi-modal in situ transcriptomics by combining microscopy and sequencing technologies and methods. In some aspects, the methods provided herein involve analyzing one or more analyte panels in a sample using a first imaging modality or set of imaging modalities. Based on said analysis, a different analyte panel and/or one or more different imaging modalities can be selected for subsequent analysis.

Provided herein are methods, compositions, and systems for transposon loading. Transposons are loaded with nucleic acid molecules, allowing for transposition reactions of cellular nucleic acids. The present invention may improve transposon loading, yield of productive fragments, while minimizing potential nucleic acid fragment loss or cross-contamination.

Provided herein are methods, compositions, and systems for transposon loading. Transposons are loaded with nucleic acid molecules, allowing for transposition reactions of cellular nucleic acids. The present invention may improve transposon loading, yield of productive fragments, while minimizing potential nucleic acid fragment loss or cross-contamination.