Figure 1. . . Morphologic changes in Norwalk virus (NV)–infected 3-dimensional INT-407 aggregates. Phase contrast micrographs of 3-dimensional intestinal aggregates cultured in the rotating wall vessel bioreactor and subsequently inoculated with live NV (panels A–C), inactivated NV (γ-inactivated) (panels D–F), or phosphate-buffered saline (mock-uninfected control) (panels G–I) at 6, 12, and 24 h after inoculation. Arrows indicate cells (or cellular debris) that were released from the support beads. The beads appear as large, distinct spheres after the removal of bound cells. Original magnification ×20.