Provided is a method for sequencing DNA, which comprises: (a) obtaining a
target DNA population comprising one or more single-stranded DNAs to be
sequenced, each of which is present in a unique amount and bears a primer
to provide a double-stranded portion of the DNA for ligation thereto; (b)
contacting the DNA population with an array of hybridisation probes, each
probe comprising a label cleavably attached to a known base sequence of
predetermined length, the array containing all possible base sequences of
that predetermined length; (c) removing all unligated probes; followed by
the steps of: (d) cleaving the ligated probes to release each label; (e)
recording the quantity of each label; and (f) activating the extended
double-stranded portion to enable ligation thereto; wherein (g) steps (b)
to (f) are repeated in a cycle for a sufficient number of times to
determine the sequence of the or each single-stranded DNA by determining
the sequence of release of each label.