title: Sample RS
design: The paired-end sequencing library was prepared using Illumina TruSeq Nano DNA LT Library  Preparation Kit. 200ng gDNA was fragmented by Covaris to generate a mean fragment  distribution of 550bp. Covaris shearing generates dsDNA fragments with 3' or 5' overhangs. The  fragments were then subjected to end-repair. This process converts the overhangs resulting from  fragmentation into blunt ends using End Repair Mix. The 3' to 5' exonuclease activity of this mix  removes the 3' overhangs and the 5' to 3' polymerase activity fills in the 5' overhangs. A single  ‘A’ nucleotide is added to the 3’ ends of the blunt fragments to prevent them from ligating to one  another during the adapter ligation reaction. A corresponding single ‘T’ nucleotide on the 3’ end  of the adapter provides a complementary overhang for ligating the adapter to the fragment. This  strategy ensures a low rate of chimera (concatenated template) formation. Indexing adapters  were ligated to the ends of the DNA fragments, preparing them for hybridization onto a flow cell. The ligated products were purified using SP beads supplied in the kit. The size-selected  product was PCR amplified as described in the kit protocol.