An illustration of dilution-based sequencing. (i) The DNA fragments are separated into multiple low-concentration dilutions. (ii) After sequencing and mapping an aliquot, mapped reads form clusters which correspond to DNA fragments. (iii) Clusters are merged into read fragments and result in natural fragments (a), (b) and a chimeric fragment (c). Chimeric fragments are produced when short reads derived from multiple DNA fragments are regarded as one cluster.