Northern blot analysis using a DIG-labeled PCR fragment specific for saeRS (probe 4 [Table 2]). (A) RNA isolated from strains Newman (lanes 1 and 3) and ISP479C (lanes 2 and 4) grown to the mid-exponential-growth phase (lanes 1 and 2) or the post-exponential growth phase (lanes 3 and 4). (B) RNAs of strain Newman (lane 11) and different clinical isolates (lane 1, GN81; lane 2, GN435I; lane 3, W674; lane 4, W678; lane 5, W681; lane 6, W713; lane 7, CFN724; lane 8, CFN726; lane 9, W684; lane 10, W710) grown to the post-exponential-growth phase. Lanes 1 and 2, nasal isolates from healthy controls; lanes 3 to 6, 9, and 10, wound isolates; lanes 7 and 8, isolates from patients with cystic fibrosis.