FIG. 2.

Destabilization of λprm240 lysogens after medium and temperature shift. Cultures were grown and sampled as described in Materials and Methods. All measurements were from the same experiment and are separated for clarity. Strains were JL5932 and JL6799 (recA⁺), and JL5904 and JL6112 (ΔrecA). (A) Free phage levels for all strains. Note the logarithmic scale. (B and C) Growth curves for recA⁺ (B) and recA mutant (C) lysogens. OD₅₉₀, optical density at 590 nm. Cell debris from lysis of λprm240 lysogens made a minor contribution to the OD₅₉₀ at later times.