Figure 2. Determining if soluble signal molecules are involved.

Aflatoxin B₁ production in Spin-X centrifuge filter units (A). Tubes spun every 3 hrs for first 24 hrs and filtrates from tubes exchanged (1 and 2); or filtrates added back to itself (3 and 4) (B). Toxigenic isolate 53 and atoxigenic 51 were grown for a total of 5 days.