Version 3This protocol describes the use of Cesium Chloride to purify viruses with an optional dialysis step to remove the CsCl. DNase I treatment, CsCl purification, and sucrose purification methods were compared using replicated viral metagenomics in Hurwitz et al. 2012.References:Hurwitz, B.L., Deng, L., Poulos, B.T., & Sullivan, M.B. (2012). Evaluation of methods to concentrate and purify ocean virus communities through comparative, replicated metagenomics. Environ Microbiol. 15(5), 1428\u20131440. doi:10.1111\/j.1462-2920.2012.02836.x.