A method for detecting or enriching of a target deoxyribonucleic acid present in a nucleic acid sample, said method comprising: (a) fragmenting a nucleic acid sample to generate nucleic acid fragments including a target fragment containing said target DNA; (b) rendering said fragments, including said target fragment, partially single-stranded, wherein the single-stranded portion includes an end portion, and wherein the length of the single-stranded end portion is sufficient to allow hybridization of at least part of the single-stranded end portion of said target fragment to the probe of step (c); (c) contacting the partially single-stranded fragments of step (b) with oligonucleotides A and B of a single target-specific nucleic acid probe, wherein: (i) oligonucleotide A is a single-stranded oligonucleotide comprising at one end a first target-specific part comprising at least 10 nucleotides complementary in sequence to at least part of said single-stranded portion of said target fragment, and comprising at the other end a second non-target-specific part which comprises a nucleotide sequence complementary to at least a portion, including one end, of oligonucleotide B of the probe, and (ii) oligonucleotide B is a single-stranded oligonucleotide which comprises at least one element for enrichment of said target fragment, and of which at least a portion, including one end, is complementary in sequence to the second non-target-specific part of oligonucleotide A, such that said target fragment becomes annealed to said probe through hybridization to the first target-specific part of oligonucleotide A resulting in only one target-specific probe-binding event per target fragment; (d) ligating oligonucleotide B of said probe to the end of said target fragment which is hybridized to oligonucleotide A of said probe to produce a probe-target fragment hybrid; and (e) enriching for said probe-target fragment hybrid by means of said at least one enrichment element, wherein: (i) the at least one element for enrichment in oligonucleotide B of the probe comprises an element for immobilization to a solid phase, and wherein enrichment in step (e) is by means of immobilization to a solid phase by means of the immobilization element; and/or (ii) the at least one element for enrichment in oligonucleotide B of the probe comprises an amplification primer binding site, and wherein enrichment in step (e) is by means of amplifying the target fragment via the amplification primer binding site. (a) fragmenting a nucleic acid sample to generate nucleic acid fragments including a target fragment containing said target DNA; (b) rendering said fragments, including said target fragment, partially single-stranded, wherein the single-stranded portion includes an end portion, and wherein the length of the single-stranded end portion is sufficient to allow hybridization of at least part of the single-stranded end portion of said target fragment to the probe of step (c); (c) contacting the partially single-stranded fragments of step (b) with oligonucleotides A and B of a single target-specific nucleic acid probe, wherein: (i) oligonucleotide A is a single-stranded oligonucleotide comprising at one end a first target-specific part comprising at least 10 nucleotides complementary in sequence to at least part of said single-stranded portion of said target fragment, and comprising at the other end a second non-target-specific part which comprises a nucleotide sequence complementary to at least a portion, including one end, of oligonucleotide B of the probe, and (ii) oligonucleotide B is a single-stranded oligonucleotide which comprises at least one element for enrichment of said target fragment, and of which at least a portion, including one end, is complementary in sequence to the second non-target-specific part of oligonucleotide A, such that said target fragment becomes annealed to said probe through hybridization to the first target-specific part of oligonucleotide A resulting in only one target-specific probe-binding event per target fragment; (i) oligonucleotide A is a single-stranded oligonucleotide comprising at one end a first target-specific part comprising at least 10 nucleotides complementary in sequence to at least part of said single-stranded portion of said target fragment, and comprising at the other end a second non-target-specific part which comprises a nucleotide sequence complementary to at least a portion, including one end, of oligonucleotide B of the probe, and (ii) oligonucleotide B is a single-stranded oligonucleotide which comprises at least one element for enrichment of said target fragment, and of which at least a portion, including one end, is complementary in sequence to the second non-target-specific part of oligonucleotide A, (d) ligating oligonucleotide B of said probe to the end of said target fragment which is hybridized to oligonucleotide A of said probe to produce a probe-target fragment hybrid; and (e) enriching for said probe-target fragment hybrid by means of said at least one enrichment element, (i) the at least one element for enrichment in oligonucleotide B of the probe comprises an element for immobilization to a solid phase, and wherein enrichment in step (e) is by means of immobilization to a solid phase by means of the immobilization element; and/or (ii) the at least one element for enrichment in oligonucleotide B of the probe comprises an amplification primer binding site, and wherein enrichment in step (e) is by means of amplifying the target fragment via the amplification primer binding site.