Induction of Heritable New Type in Type Specific Strains of H. influenzae.

Summary 1. Normal strains of types b and d H. influenzae have been directly transformed to new types of H. influenzae; type b was changed to types a, c and d, and type d into types a, b and c. 2. The rate of occurrence in type d populations of cells susceptible of transformation has been shown to be not significantly different from that found earlier in R cell populations derived from type d. Comparisons in the presence of more potent anti d antibody have been made subsequently between populations of Rd and type d for frequency of cells susceptible (initially or during growth for 24 hours) to transformation to type c. No real differences could be demonstrated when this more efficient selective agent was used.