FIG. 4.

Two-cycle growth inhibition assays. (A) Comparison of flow cytometry versus microscopy for evaluation of parasite growth using dialyzed serum from exposed and nonexposed donors. (B) Comparison of results from growth inhibition assays performed with or without intermittent agitation, using dialyzed serum samples. Results are expressed as a percentage of parasite growth among nonexposed serum controls. S1 to 4, sera from nonexposed Australian donors; 1 to 24, sera from adults living in Papua New Guinea. (C) Dialyzed sera were tested in repeat growth inhibition assays over two cycles of replication, with evaluation of parasitemia by flow cytometry. Results were significantly correlated (r = 0.872, P < 0.001). Data are expressed as percentages of parasite growth among nonexposed serum controls.