Patent attributes
A method of identifying a base at a target position in a single-stranded sample DNA sequence, the method characterised by the steps of: (i) providing an oligonucleotide probe which is capable of hybridising to the sample DNA sequence such that the 3′ nucleotide of the probe overlaps the target position, the probe being blocked at the 3′ end to prevent extension by DNA polymerase but permitting 3′-5′ exonuclease cleavage; (ii) incubating the sample DNA sequence with the probe in the presence of (a) a composition having 3′-5′ exonuclease activity and (b) nucleotide triphosphates, under conditions that allow hybridisation of the probe to the sample DNA sequence; and (iii) detecting, directly or indirectly, cleavage of the 3′ nucleotide of the probe.
