Sequencing of naturally dense DNA from synchronised human cells
Natural modifications of fragmented human genomic DNA were analysed by  density equilibrium centrifugation and DNA sequencing. Genomic DNA was  isolated from synchronised human cells, fragmented by sonication and  separated on caesium sulphate density gradients. DNA fractions of bulk  and increased density were isolated, purified and sequenced using  Illumina technology. The DNA sequencing analyses revealed the existence  of many discrete sites on the human genome with an increased natural density.