Figure 2. Antigen-specific IgG antibodies in naïve and vaccinated mice.

IgG antibodies in C57BL/6 mice vaccinated twice with pDNA encoding the nine Pks synthase domains and boosted with the homologous recombinant protein. Sera were collected three weeks after the protein boost and tested by ELISA, using serial twofold dilutions, starting at 1∶50. Open circles: naive mice, closed circles vaccinated mice. Results presented as mean O.D. values ± SD of 4–6 mice tested individually.