by using engineered sequence specific dna nuclease , the composition , reagent kit and method of the present invention can cut and release a dna sequence of interest 1 × 10 4 - 1 × 10 7 - base pairs long from a source dna as large as the whole genome . the ssdn further includes an affinity tag or is bound to a solid support that facilitates the isolation of the dna sequence of interest . the ssdn can include a reca and ref combination , a transcription activator like effector nuclease , or a sequence specific chemical nuclease . when applied to genomic sequencing , specific region of interest in the genome can be cut and isolated . because the irrelevant part of the genome is removed from the sequencing reaction , the speed , cost , and accuracy of genomic sequencing can be improved .