Figure 9.28: Benzer developed a procedure for mapping
rII
mutants.
Two different
rII
mutants (
a
−
b
+
and
a
+
b
−
) are isolated on
E. coli
B cells. Only the
a
+
b
+
recombinant can grow on
E. coli
K, allowing these recombinants to be identified.