FIG. 3.

Recognition of native Pfs25 antigen from purified gametes and zygotes of P. falciparum by Western blot analysis. Electrophoresis was performed under nonreducing conditions and blotted with pooled monkey sera (1:2,000 dilution). Lanes: 1, VR1020/25 DNA-DNA; 2, VR1020/27-25 DNA-DNA; 3, VR1020 alone; 4, recombinant Pfs25 alone. The sera used were collected 7 weeks after four DNA immunizations and 3 weeks after one protein immunization (group 5). The values on the left are molecular sizes in kilodaltons.