library with 170 bp insert size
5 µg of genomic DNA was fragmented by nebulization with compressed nitrogen gas. We then polished the DNA ends and added an “A” base to the ends of the DNA fragments. Next, the DNA adaptors (Illumina) with a single “T” base overhang at the 3’ end were ligated to the above products. We then purified the ligation products on a 2% agarose gel, and excised and purified gel slices for each insert size (Qiagen Gel Extraction Kit). We required the insert size of a library to fall in a narrow range (peak – peak * 10%, peak   peak * 10%), in order to facilitate the assembly process.