targets were used as targets for a beadchip assay step 4 the captured targets on the beads were detected by incubation with fluorescent labeled ligands that have high affinity to the labels such as cy3 conjugated streptavidin for detection of the biotinylated targets followed by read detection fig3 the cleavage dna products described in example 2 were used in a beadchip hmap assay briefly each of the depurination treatment products i e those resulting from 0 10 13 15 17 20 25 and gt 25 min depurination was used as a target in the hmap beadchip assay hybridization intensities of the targets to a panel of sequence specific probes were analyzed as shown in fig4 intensity for probe a and probe c decreases as depurination time increases suggesting increasing cleavage of long dna targets into smaller fragments from the depurination however intensities for probes b d e and f first increase in partial depurination then decrease in further depurination suggesting partial cleavage results in release of certain target sequences that were unavailable in long dnas due to other factors such as secondary structure of the targets fig4 dna oligonucleotide probes used in the hybridization mediated assay may contain a terminal reactive group an internal spacer molecule and a stretch of nucleotides that are complementary to target dnas of interest the oligonucleotide probes can be complementary to the sense strand or the antisense strand of the dna molecules one or the other strand is selected to.