FIGURE 2: Spot test assay showing relative fitness differences between wild-type, SCV, and suppressed mutants. For each strain 10 colonies from an LB agar plate incubated at 37°C for 24 hours were suspended in 1 mL 0.9% NaCl. Each spot represents 5 µL of cell suspension pipetted onto LB agar, with 10-fold dilutions as indicated, incubated at 37°C for 24 hours before photography. The SCV mutation is menB D151N, and the suppressed mutants shown are isogenic strains carrying suppressor mutations in srrA and tRNA-Asp, respectively.