Fig. 1
Comparison of avidity indexes for 5 merozoite antigens using 3 different chaotropic agents. Antigen-coupled beads were incubated with a 1:600 dilution of the positive control (PC) and plasma from adults (#1–#5) living in a high malaria transmission area in Cameroon. After incubation, Ab-bound beads were incubated with 4 M GdHCl for 10 min, 8 M urea for 10 min, or 3 M NH4SCN for 30 min. Results show mean AI values (i.e., the percentage of Ab remaining bound after treatment with salt) ± SD for 3 replicate samples. Antigens included: AMA1 (3D7), EBA-175, MSP1 (3D7), MSP2 (FC27) and MSP3 (HB3). Baseline (no salt) MFI values [mean ± SD] for the 6 plasma samples (PC + 5 adults) were as follows: a AMA1 = 23,677 ± 1079 MFI; b EBA-175 = 22,002 ± 1573 MFI; c MSP1 = 11,196 ± 1405 MFI; d MSP2 = 5702 ± 2282; and e MSP3 = 4128 ± 1232 MFI