Abstract: Methods of detecting target polynucleotide sequences may include introducing one or more nucleic acid analytes to a first reaction mixture comprising a single-stranded probe oligonucleotide A0, a pyrophosphorolysing enzyme, and a ligase. The analyte may anneal to the single-stranded probe oligonucleotide A0 to create a first intermediate product which is at least partially double-stranded, where the 3? end of A0 forms a double-stranded complex with the analyte and where A0 is pyrophosphorylsed in the 3?-5? direction from the 3? end to create at least a partially digested strand A1. A1 may undergo ligation to form oligonucleotide A2. The methods may also include detecting a signal derived from the formed oligonucleotides, and inferring therefrom the presence or absence of the target polynucleotide sequence in the analyte.

Abstract: Methods of detecting target polynucleotide sequences may include introducing one or more nucleic acid analytes to a first reaction mixture comprising a single-stranded probe oligonucleotide A0, a pyrophosphorolysing enzyme, and a ligase. The analyte may anneal to the single-stranded probe oligonucleotide A0 to create a first intermediate product which is at least partially double-stranded, where the 3? end of A0 forms a double-stranded complex with the analyte and where A0 is pyrophosphorylsed in the 3?-5? direction from the 3? end to create at least a partially digested strand A1. A1 may undergo ligation to form oligonucleotide A2. The methods may also include detecting a signal derived from the formed oligonucleotides, and inferring therefrom the presence or absence of the target polynucleotide sequence in the analyte.

Abstract: A method of detecting a target polynucleotide sequence in a given nucleic acid analyte characterised by the steps of: a. annealing the analyte to a single-stranded probe oligonucleotide A0 to create a first intermediate product which is at least partially double-stranded and in which the 3? end of A0 forms a double-stranded complex with the analyte target sequence; b. pyrophosphorolysing the first intermediate product with a pyrophosphorolysing enzyme in the 3?-5? direction from the 3? end of A0 to create partially digested strand A1 and the analyte; c. (i) annealing A1 to a single-stranded trigger oligonucleotide B and extending the A1 strand in the 5?-3? direction against B; or (ii) circularising A1 through ligation of its 3? and 5? ends; or (iii) ligating the 3? end of A1 to the 5? end of a ligation probe oligonucleotide C; in each case to create an oligonucleotide A2; d. priming A2 with at least one single-stranded primer oligonucleotide and creating multiple copies of A2, or a region of A2; and e.

Abstract: A method of detecting a target polynucleotide sequence in a given nucleic acid analyte characterised by the steps of: a. annealing the analyte to a single-stranded probe oligonucleotide A0 to create a first intermediate product which is at least partially double-stranded and in which the 3? end of A0 forms a double-stranded complex with the analyte target sequence; b. pyrophosphorolysing the first intermediate product with a pyrophosphorolysing enzyme in the 3?-5? direction from the 3? end of A0 to create partially digested strand A1 and the analyte; c. (i) annealing A1 to a single-stranded trigger oligonucleotide B and extending the A1 strand in the 5?-3? direction against B; or (ii) circularising A1 through ligation of its 3? and 5? ends; or (iii) ligating the 3? end of A1 to the 5? end of a ligation probe oligonucleotide C; in each case to create an oligonucleotide A2; d. priming A2 with at least one single-stranded primer oligonucleotide and creating multiple copies of A2, or a region of A2; and e.

Abstract: A method of detecting a target polynucleotide sequence in a given nucleic acid analyte characterised by the steps of: a. annealing the analyte to a single-stranded probe oligonucleotide A0 to create a first intermediate product which is at least partially double-stranded and in which the 3? end of A0 forms a double-stranded complex with the analyte target sequence; b. pyrophosphorolysing the first intermediate product with a pyrophosphorolysing enzyme in the 3?-5? direction from the 3? end of A0 to create partially digested strand A1 and the analyte; c. (i) annealing A1 to a single-stranded trigger oligonucleotide B and extending the A1 strand in the 5?-3? direction against B; or (ii) circularising A1 through ligation of its 3? and 5? ends; or (iii) ligating the 3? end of A1 to the 5? end of a ligation probe oligonucleotide C; in each case to create an oligonucleotide A2; d. priming A2 with at least one single-stranded primer oligonucleotide and creating multiple copies of A2, or a region of A2; and e.