The isolation and characterisation of a plaque-forming derivative of bacteriophage Mu carrying a fragment of Tn3 conferring ampicillin resistance.

We have isolated a plaque-forming derivative of phage Mu which carries a determinant for ApR. The biological properties of this MuAp phage are similar to those of normal Mu. Its genome contains a 1.1 kb substitution where Mu DNA from the right end of the G region has been replaced by a similar length of DNA from the transposon Tn3. This fragment of Tn3 DNA carries the ApR gene, but is no longer capable of independent transposition.