antibiotic-sensitive E. coli cells to a
recombinant plasmid allows integration
of the plasmid DNA into the bacterial DNA (transformation).
The bacterial cells can then express the genes found in the
plasmid, which in a cloning experiment include those for resistance
to antibiotics. Growth of individual bacterial colonies on
media with antibiotics then indicates cells
that have successfully integrated plasmid DNA along
with the cloned insert DNA.