Figure 2. Complementation of the RNase J deletions.

Spotting and interpretation was carried out as in Figure 1, but with 10 µg/ml chloramphenicol added to both the overnight culture and in the agar plates, to ensure against loss of the complementing plasmids. pEB01 is the empty plasmid. The faint white rings seen randomly distributed on the RH medium are not colonies, but are air bubbles that often form inside the agar matrix during incubation of this medium.