FIG. 1.

Binding of the anti-NspA Mabs by ELISA. (A) Binding to microvesicles prepared from an E. coli strain expressing recombinant NspA (closed bars) or from the same E. coli strain transformed with the plasmid without the nspA gene (open bars). Data for the microvesicles containing rNspA were obtained at an antibody concentration of 60 ng/ml, whereas the negative control microvesicles were tested at 600 ng/ml. (B) Binding to lauroyl sarcosinate-insoluble outer membranes prepared from N. meningitidis serogroup B strains BZ198 (closed bars) or BZ198ΔNspA (open bars), in which the gene encoding NspA had been inactivated. The antibody concentrations were the same as those for panel A. (C) Binding to Ni-NTA Sepharose metal affinity-purified HisTag-NspA. The anti-NspA MAbs were tested at 5 μg/ml, the irrelevant MAb was tested at 50 μg/ml, and the polyclonal anti-HisTag NspA antisera were tested at a dilution of 1:108,000.