Samples are passed through 0.025 pore sized um filters to capture the viral-sized component from a water sample

In this image, three funnels containing seawater samples from coral mesocosms are passed through 0.025 um pore size filters. The samples have already been filtered through 0.2 um pore size filters to remove larger microorganisms such as bacteria, so the 0.025 um filters will capture primarily the viral size fraction of the mesocosm microbial community.