Fig. 7.

Frequencies of appearance of insertion mutants from wild-type and non-motile cells in soft agar Overnight LB cultures of strains CAT, CAT_ΔAB and CAT_ΔfliC were washed once using 1x M9 salts and then diluted to an OD₆₀₀ of 1. Four microlitres was streaked onto soft NB agar plates (0.4 % NB+0.3 % agar), and the plates were incubated at 30 °C. After 18 h, the total populations and IS insertional mutant populations were determined as described in the legend to Fig. 4. Three soft agar plates were used for each strain. CAT_ΔAB and CAT_ΔfliC are non-motile.