FIG. 2.
Isoelectric focusing and CAS overlay for detection of siderophores in P. syringae. Siderophores were extracted from concentrated culture supernatants using XAD-4 resin at pH 3.0. After separation by isoelectric focusing, the polyacrylamide gel was overlaid with a thin layer of CAS agar to visualize siderophore activity. Lane 1, P. syringae pv. syringae 22d/93ΔSid; lane 2, purified pyoverdin of P. syringae; lane 3, P. syringae pv. syringae 22d/93; lane 4, P. syringae pv. glycinea 1a/96; lane 5, P. syringae pv. syringae 22d/93ΔPvd.