Prophage S2 mutants in Haemophilus influenzae: a technique for their production and isolation.

A procedure utilizing nitrosoguanidine has been developed to produce defective and temperature-sensitive mutants of prophage (S2) in lysogenic Haemophilus influenzae. The system should be generally applicable to all temperate phage systems. At saturating concentrations of phage DNA, more than 25 percent of recipient mutant lysogenic bacteria can be transformed to the wild type.