FIG. 6.

Determination of cell size (A) and chromosome content (B-D) by flow cytometry. Cells used were exponentially growing in different growth media: LB broth (A-B), minimal glucose + CAA (C), and minimal glucose (D). Depending upon the growth medium, the two major peaks of Hoechst fluorescence represent cells with either four and eight (B) or two and four (C-D) chromosomes, but their ratio varied depending upon the genotype of the cells as identified to the right of the figure (see Table 3 for details). The cells used were either MG1655 (WT) or its isogenic derivatives. The dam mutant (BR2786) is from our lab collection and is not derived from MG1655.