Fig. 8.

Effects of agar concentration on the appearance of insertional mutants. An overnight LB culture of CAT was washed once and diluted to OD₆₀₀ of 1. Four microlitres of diluted culture was streaked onto NB agar plates (0.4 % NB+0–1.2 % agar), and the plates were incubated at 30 °C. After 18 h, the total populations and mutant populations in the plates with 0–0.4 % agar were determined as described in the legend to Fig. 4. For the plates with 0.6 % agar or above, the cells were washed off the plates without breaking the agar, and the total populations and mutant populations were determined as described in the legend to Fig. 4. These experiments were conducted in triplicate, and error bars represent sd.