Figure 3.

Release of T5 genome in 5 mM spermine bulk solution. (A and B) Typical electron micrographs of the annular structures (70–100 nm in diameter) formed 1–2 min after adding T5 phages to FhuA. (C) Large toroids are formed after 15 min of incubation at pH 7. (D) DNA released in solution at pH 8. DNA condensates appear as hollow cylinders exhibiting highly ordered DNA strands. On circular view, DNA is disposed in concentric arcs with a 26-Å spacing (black arrow). On tilted view (marked by an asterisk), a regular disposition of DNA strands is visible (arrowhead). (Bar = 100 nm.)