TLC and LC-MS analyses of total RL extracts from the PAO1 and Psl/Pel-inducible strains. (A) TLC analysis of RL extracted from cultures of the corresponding strains grown in the absence (−) or presence (+) of 1% arabinose. (B) LC-MS peak of Rha-C10-C10 (m/z 503) (mono-RL). (C) Relative abundances of Rha-C10-C10 in corresponding RL extracts analyzed by LC-MS. (D) LC-MS peak of Rha-Rha-C10-C10 (m/z 649) (di-RL). (E) Relative abundances of Rha-Rha-C10-C10 in corresponding RL extracts analyzed by LC-MS. The relative abundances of Rha-C10-C10 and Rha-Rha-C10-C10 were normalized to the levels in PAO1 (respectively, 3,646,111 and 1,653,883 without arabinose and 2,722,080 and 2,223,691 with 1% arabinose). The corresponding peaks of mono-RL and di-RL are indicated in panels B and C. ESI, electrospray ionization.