In various aspects, the present disclosure provides methods, compositions, reactions mixtures, kits, and systems for sequencing both RNA and DNA from a single source sample. In some embodiments, RNA is treated so as to differentiate RNA sequences from DNA sequences derived from the same sample. In some embodiments, the RNA and DNA are cell-free polynucleotides.

Provided herein, in some aspects, are methods of imaging molecules without a microscope or other specialized equipment, referred to herein as “microscope-free imaging (MFI).” Herein, “molecular instruments” (e.g., DNA-based and protein-based molecules) are used, instead of microscopes, in a “bottom-up” approach for inspecting molecular targets.

Provided herein, in some aspects, are methods of imaging molecules without a microscope or other specialized equipment, referred to herein as “microscope-free imaging (MFI).” Herein, “molecular instruments” (e.g., DNA-based and protein-based molecules) are used, instead of microscopes, in a “bottom-up” approach for inspecting molecular targets.

The present invention provides methods and systems for sequencing long nucleic acid fragment. The present invention also provides a method of sequencing a target polynucleotide with fewer probes. Further, the present invention provides a method of sequencing a target polynucleotide with longer reads. Locus-specific, ligation-assisted sequencing/genotyping method and ligation-captured sequencing method are also provided in the present invention. The methods of the present invention allow low-cost, high-throughput and accurate sequencing of nucleic acids.

Methods of coupling adaptors to a target nucleic acid include coupling a first adaptor to a first end of the target nucleic acid to form a coupled first adaptor. A portion of a second adaptor is hybridized to a portion of the coupled first adaptor to form a hybridized second adaptor having a single-stranded 3′-end. The hybridized second adaptor is coupled to a second end of the target nucleic acid to form an adaptor-flanked product having at least a part of the first adaptor coupled to the first end of the target nucleic acid and at least a part of the second adaptor coupled to the second end of the target nucleic acid. These methods can minimize the formation of adaptor-dimers that may be problematic in subsequent complementary nucleic acid strand synthesis, amplification, and sequencing.

Methods of coupling adaptors to a target nucleic acid include coupling a first adaptor to a first end of the target nucleic acid to form a coupled first adaptor. A portion of a second adaptor is hybridized to a portion of the coupled first adaptor to form a hybridized second adaptor having a single-stranded 3′-end. The hybridized second adaptor is coupled to a second end of the target nucleic acid to form an adaptor-flanked product having at least a part of the first adaptor coupled to the first end of the target nucleic acid and at least a part of the second adaptor coupled to the second end of the target nucleic acid. These methods can minimize the formation of adaptor-dimers that may be problematic in subsequent complementary nucleic acid strand synthesis, amplification, and sequencing.

Disclosed herein are compositions and methods related to the elimination of molecules of a selected sequence from a nucleic acid sample or from an sequence dataset resulting from the sequencing of a sample, for example to exclude such molecules from downstream analysis or sequencing, or to exclude such sequences from a downstream data set.

Disclosed herein are compositions and methods related to the elimination of molecules of a selected sequence from a nucleic acid sample or from an sequence dataset resulting from the sequencing of a sample, for example to exclude such molecules from downstream analysis or sequencing, or to exclude such sequences from a downstream data set.

Kits and methods of using the kits for analyzing macromolecules, including peptides, polypeptides, and proteins, employing nucleic acid encoding are disclosed. The sample analysis kits employ nucleic acid encoding and/or nucleic acid recording of a molecular interaction and/or reaction, such as recognition events (e.g., between an antigen and an antibody, between a modified terminal amino acid residue, or between a small molecule or peptide therapeutic and a target, etc.). Additional barcoding reagents, such as those for cycle-specific barcoding (e.g., “clocking”), compartment barcoding, combinatorial barcoding, spatial barcoding, or any combination thereof, may be included in the kits. The sample may comprise macromolecules, including peptides, polypeptides, and proteins, and the recording may generate molecular interaction and/or reaction information, and/or polypeptide sequence information. The kits may be used in high-throughput, multiplexed, and/or automated analysis, and are suitable for analysis of a proteome or subset thereof.

Kits and methods of using the kits for analyzing macromolecules, including peptides, polypeptides, and proteins, employing nucleic acid encoding are disclosed. The sample analysis kits employ nucleic acid encoding and/or nucleic acid recording of a molecular interaction and/or reaction, such as recognition events (e.g., between an antigen and an antibody, between a modified terminal amino acid residue, or between a small molecule or peptide therapeutic and a target, etc.). Additional barcoding reagents, such as those for cycle-specific barcoding (e.g., “clocking”), compartment barcoding, combinatorial barcoding, spatial barcoding, or any combination thereof, may be included in the kits. The sample may comprise macromolecules, including peptides, polypeptides, and proteins, and the recording may generate molecular interaction and/or reaction information, and/or polypeptide sequence information. The kits may be used in high-throughput, multiplexed, and/or automated analysis, and are suitable for analysis of a proteome or subset thereof.