Dot plots showing complement activation by fractions eluted at different EDTA concentrations.

<p>The 50 mM fraction (Panel D) had maximal activity that was comparable to that of the crude culture supernatant (Panel A). Sham supernatant eluted at 50 mM EDTA had no complement activity.</p

Silver stained PAGE gel showing three distinct proteins of sizes 40–64 kDa.

<p>Lanes marked MW =  molecular weight marker, 1 =  crude <i>P. falciparum</i> culture supernatant, 2 =  MBL binding proteins eluted with 50 mM EDTA.</p

Remnant complement components of AP (6%), MBL (43%) and CP (65%) following activation by <i>P. falciparum</i> culture supernatant.

<p>Sham supernatant did not lead to depletion of complement components.</p

Photomicrographs showing C3b deposition on erythrocytes (fluorescent spots) following activation of complement by supernatant from sham culture (Panel A) and <i>P. falciparum</i> culture (Panel B) harvested at schizont stage.

<p>Note the fluorescent spots are in clusters, which is the hallmark of CR1 distribution on erythrocytes <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0105093#pone.0105093-Taylor1" target="_blank">[33]</a>. C3b was detected by Alexa 488 conjugated to anti-C3b IgG, and observed under high power magnification using an Olympus BX41 fluorescent microscope (Olympus America Inc. USA).</p

Representative dot plots showing % C3b deposition on RBC following complement activation by sham and malaria culture supernatants at 2% parasitemia.

<p>% C3b deposition for sham supernatant was (3.77%), rings (8.22%), late trophozoites (11.10%) and schizontes (17.70%).</p

Complement activation by culture supernatant collected from different growth stages and parasite densities of <i>P. falciparum</i>.

<p>At all parasitemia levels, % C3b deposition was highest with supernatant harvested at schizont stage.</p

Merozoite lectin binding proteins identified by Matrix-assisted laser desorption/ionization (MALDI).

<p>Merozoite lectin binding proteins identified by Matrix-assisted laser desorption/ionization (MALDI).</p

Species-specific primers and probes for detecting <i>Plasmodium</i> parasites.

<p>Species-specific primers and probes for detecting <i>Plasmodium</i> parasites.</p

Trends in malaria prevalence by diagnostic method among the study participants that did not develop clinical malaria during the 112-day study.

<p>At every visit, malaria prevalences are highest when detected by <i>Pf</i>HRP-2 ELISA and qRT-PCR methods and lowest when measured with microscopy and <i>p</i>LDH ELISA.</p

Comparison of routine microscopy, <i>p</i>LDH/<i>Pf</i>HRP-2 ELISA and qPCR for a group of study participants who had acute blood smears prepared at sick visits.

<p>Each column (1–38) represents one blood sample with the corresponding microscopy, <i>p</i>LDH/<i>Pf</i>HRP-2 ELISA and qRT-PCR results, ordered by parasite density as determined by microscopy (top graph) and antigen levels (<i>p</i>LDH/<i>Pf</i>HRP-2) or Ct values (qPCR). As the levels of parasitemia decreases, the concordance between the different methods also decreases. <i>Pf</i>HRP-2 and qPCR detect parasites densities way beyond the detection limit of microscopy.</p