The invention discloses a method and a system to detect a target nucleic acid sequence in a sample using padlock probe-based rolling circle amplification and nuclease protection. Padlock probe-based rolling circle amplification and nuclease protection may be used in combination with other detection assays to detect target nucleic acid sequences in a sample.

The invention discloses a method and a system to detect a target nucleic acid sequence in a sample using padlock probe-based rolling circle amplification and nuclease protection. Padlock probe-based rolling circle amplification and nuclease protection may be used in combination with other detection assays to detect target nucleic acid sequences in a sample.

Disclosed herein are methods for detecting presence of a nucleotide variant in a target nucleic acid utilizing a nuclease protection assay. The methods include contacting a sample with at least two probes, wherein the first probe is complementary to the wild-type (non-variant) nucleotide(s) at the nucleotide variant position(s) in the target nucleic acid and the second probe is complementary to the variant nucleotide(s) at the nucleotide variant position(s) in the target nucleic acid, under conditions sufficient for the probes to hybridize to the target nucleic acid, producing a mixture of hybridized and unhybridized nucleic acids. The mixture is contacted with a nuclease specific for single-stranded nucleic acid molecules under conditions sufficient to remove unhybridized nucleic acid molecules (or unhybridized portions of nucleic acid molecules). The presence of the at least two probes is then detected, thereby detecting the presence of the variant and/or non-variant target nucleic acid in the sample.

The invention provides methods of detecting a feature of interest in a nucleic acid sample by negatively and positively enriching the sample for segments that contain the feature of interest. Negative enrichment may include digestion of nucleic acids that do not contain the segments, and positive enrichment may include purification of the segments. The methods are useful for diagnostic of genetic elements, e.g., elements indicative of cancer.

The invention provides methods of detecting a feature of interest in a nucleic acid sample by negatively and positively enriching the sample for segments that contain the feature of interest. Negative enrichment may include digestion of nucleic acids that do not contain the segments, and positive enrichment may include purification of the segments. The methods are useful for diagnostic of genetic elements, e.g., elements indicative of cancer.

The invention provides methods for detecting small mutations and structural alterations in DNA by using binding proteins to protect those features while digesting unprotected DNA in a sample. To detect small mutations, a protein that binds exclusively to the mutation of interest, and not to wild-type, is used. For structural alterations, binding proteins are used that flank a breakpoint of the alteration. After digestion of unbound, unprotected nucleic acid in the sample, the mutation- or breakpoint-containing segment remains as an isolated DNA fragment. The sample is then assayed to detect any fragment of DNA and the detection of the fragment indicates the presence of the mutation or breakpoint in the subject.

The invention provides methods for detecting small mutations and structural alterations in DNA by using binding proteins to protect those features while digesting unprotected DNA in a sample. To detect small mutations, a protein that binds exclusively to the mutation of interest, and not to wild-type, is used. For structural alterations, binding proteins are used that flank a breakpoint of the alteration. After digestion of unbound, unprotected nucleic acid in the sample, the mutation- or breakpoint-containing segment remains as an isolated DNA fragment. The sample is then assayed to detect any fragment of DNA and the detection of the fragment indicates the presence of the mutation or breakpoint in the subject.

The invention provides methods for detecting small mutations and structural alterations in DNA by using binding proteins to protect those features while digesting unprotected DNA in a sample. To detect small mutations, a protein that binds exclusively to the mutation of interest, and not to wild-type, is used. For structural alterations, binding proteins are used that flank a breakpoint of the alteration. After digestion of unbound, unprotected nucleic acid in the sample, the mutation- or breakpoint-containing segment remains as an isolated DNA fragment. The sample is then assayed to detect any fragment of DNA and the detection of the fragment indicates the presence of the mutation or breakpoint in the subject.

The invention provides methods for detecting small mutations and structural alterations in DNA by using binding proteins to protect those features while digesting unprotected DNA in a sample. To detect small mutations, a protein that binds exclusively to the mutation of interest, and not to wild-type, is used. For structural alterations, binding proteins are used that flank a breakpoint of the alteration. After digestion of unbound, unprotected nucleic acid in the sample, the mutation- or breakpoint-containing segment remains as an isolated DNA fragment. The sample is then assayed to detect any fragment of DNA and the detection of the fragment indicates the presence of the mutation or breakpoint in the subject.

The invention provides methods of detecting a feature of interest in a nucleic acid sample by negatively and positively enriching the sample for segments that contain the feature of interest. Negative enrichment may include digestion of nucleic acids that do not contain the segments, and positive enrichment may include purification of the segments. The methods are useful for diagnostic of genetic elements, e.g., elements indicative of cancer.