Lysis &
plaque formation by T1 bacteriophage on E. coli
The
petri dish is covered by a uniform light grey lawn of E. coli
bacteria.
Addition of a small number of T1 bacteriophage
allows
each to infect a single bacterium, where it uses the cell's DNA
to reproduce more of itself, eventually causing lysis and
release of more
phage particles. Infection and lysis clears
a small plaque in the
bacterial lawn, which appear here
as dark grey circles.