Fig 8.

Recovery of phosphorylated lipid A species and phosphorylated dihydroceramide lipids in organic solvent extracts from subgingival plaque samples. Subgingival plaque samples were collected, pooled by individual, and extracted for lipids, as described in Materials and Methods. A sample of each lipid extract was evaluated for phosphorylated lipid A species (left) and for phosphorylated dihydroceramide lipids (right) using the same order of ion transition monitoring and instrument parameters as shown in Fig. 7. Lipid samples were injected at 5 s and 2.5 min. Note that the phosphorylated dihydroceramide lipids show at least 2 or 3 orders of magnitude greater abundance compared with the phosphorylated lipid A species in the same lipid extracts of subgingival plaque samples.