FIG. 4.

Cell mass and DNA content of subpopulations in a mixture of three species. (A) Bivariate histogram of forward light scatter versus DAPI-DNA fluorescence intensity for the mixture along with the 0.6- and 0.9-μm-diameter microspheres. Whole numbers give the number of chromosome copies contained by cells in various subpopulations. Dim indicates cells of E. coli showing very low fluorescence, and C indicates cells of C. oligotrophus undergoing chromosome replication. M., Marinobacter. (B, C, and D) Distributions of dry mass and DNA content for E. coli, Marinobacter sp. strain T2, and C. oligotrophus, respectively.