Soluble Expression and Characterization of Biologically Active Bacillus anthracis Protective Antigen in Escherichia coli

Figure 8

Indirect ELISA of PA immunized mice sera. ELISA plates were coated with 1 μg mL⁻¹ PA overnight at 4°C. Following blocking with 5% skimmed milk, the plates were incubated for one hour with serial twofold dilution of PA immunized mice sera starting from 1 : 1000 at room temperature. Plates were washed thoroughly and, after revealing with anti-mouse IgG HRP conjugate, the plates were developed by OPD. PA sera showed high antibody titer of 1.3 × 10⁵.