Identification of small circular DNA viruses in fresh water lake sample
40ml of the water sample collected was sequentially filtered through a 0.45 and a 0.2m syringe filer. Viral particles in the filtrate were precipitated with 10%w/v PEG. The precipitated particles were suspended in 1 ml of SM buffer and 200l of this was used to extract viral DNA using the High Pure Viral Nucleic acid purification kit (Roche, USA). The resulting DNA extract was amplified using rolling circle amplification with Templiphi (GE Healthcare, USA). The amplified DNA was used to generate Illumina libraries at Macrogen Inc (Korea) and sequenced on an Illumina HiSeq 2500 sequencer.