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 a method of nucleic acid sequence hybridisation comprising the steps of: a) hybridising one or more samples comprising nucleic acids containing a region of interest with at least one probe nucleic acid sequence; and b) adding to the samples a non-deoxy ribonucleic acid molecule, before or during step a). and use of non-deoxy ribonucleic molecules to block or mask a surface or to block or mask repetitive DNA sequences.

Oligonucleotides, methods and kits are provided for detecting, identifying or quantifying one or more target analytes in a sample as well as methods for immobilizing oligonucleotides onto a support surface.

Oligonucleotides, methods and kits are provided for detecting, identifying or quantifying one or more target analytes in a sample as well as methods for immobilizing oligonucleotides onto a support surface.