End-sequence profiling (ESP) (sometimes "Paired-end mapping (PEM)") is a method based on sequence-tagged connectors developed to facilitate de novo genome sequencing to identify high-resolution copy number and structural aberrations such as inversions and translocations. <br />
Briefly, the target genomic DNA is isolated and partially digested with restriction enzymes into large fragments. Following size-fractionation, the fragments are cloned into plasmids to construct artificial chromosomes such as bacterial artificial chromosomes (BAC) which are then sequenced and compared to the reference genome. The differences, including orientation and length variations between constructed chromosomes and the reference genome, will suggest copy number and structural aberration.