False colour scanning electron micrograph (SEM) of culture cells growing on microcarrier beads, photographed after 70 hours growth. Microcarrier beads are used for the large-scale production of cells and cell by-products such as viruses, vaccines (live, attenuated - inert - viruses) and drugs such as the interferons. The technique is used for growing "anchorage dependent" cells in preference to petri dishes. The available surface area on a small volume of beads is greater than that obtained from a table covered in petri dishes production aspect. Magnification: X 150 at 35mm size.