FIG. 3.

Western blot analysis of CPB2 levels in cpb2-positive genotype C vegetative culture supernatants. Genotype C isolates carrying the cpb2 gene were grown in TGY medium at 37°C to the late log phase. Culture supernatant samples from these cultures were then processed with or without concentration (10- to 50-fold) and used for Western blot analysis of CPB2. (A) Representative Western blot for CPB2. The positions of molecular weight markers are indicated on the left, and pure CPB2 was electrophoresed in the left lane as a positive control. All isolates shown have toxin genotype plc cpb cpb2. The amount of CPB2 in each sample was determined by comparing the CPB2 signal density to a CPB2 standard curve generated using purified CPB2. (B) Amount of CPB2 in each sample. ND, toxin could not be detected in culture supernatants.