FIG. 3.

Effect of dcm on plasmid stabilization by linkage of EcoRII RM gene complex. The cells were grown at 30°C in liquid medium in the absence of antibiotic selection. The fraction of cells carrying plasmid, i.e., the number of Cml^r colony formers/the number of colony formers on LB agar, were plotted as a function of the generation number. JC8679, its dcm-6 derivative carrying pNY35 (EcoRII r⁺ m⁺, Cml^r), or its restriction-negative derivative, pNY45, was examined.