Figure 1.

Purification of VLP DNA. Stool was homogenized in SM Buffer; particulate matter was spun down; supernatant was filtered at 0.22 μm to remove cells; VLPs were purified on a CsCl density gradient and treated with nuclease to eliminate unprotected DNA. The absence of bacterial cells was confirmed by staining VLP preparations for nucleic acids. VLP DNA was quantified, amplified, and pyrosequenced.