Isolation, part characterization, immunogenicity, and specificity study of Plasmodium falciparum culture supernatant.

A Plasmodium falciparum malaria blood stage antigen was isolated from in vitro parasite culture supernatant. The chemical composition of the antigen was studied by high-performance thin-layer chromatography, thin-layer chromatography, gas-liquid chromatography, and other chemical methods. Such analysis indicated it to be a glycophospholipid (GPL) and to be composed of xylose, mannose, galactose, and glucose linked to a phospholipid, but no inositol. The extracted and purified antigen's sensitivity and specificity properties were assessed by laser immuno assay and enzyme-linked immunosorbent assay. The results of the sensitivity study showed a very high malaria antibody-binding response compared to other known antigens. The specificity study of GPL antigen with different nonmalarial samples showed no positive response within the limit of significance. This isolated GPL antigen appears to be better than other antigens.