The ELISA-U: an enzyme-linked immunosorbent assay using urease as the enzyme marker for rapid detection of Plasmodium falciparum antibody in human serum.
A visual, enzyme-linked immunosorbent assay using urease (ELISA-U) as the enzyme marker was adapted for rapid detection of antibody against Plasmodium falciparum. Flat-bottom, 96-well microtiter plates were coated with P. falciparum soluble antigen obtained by saponin and NP-40 treatment of parasite cultures. Antibody was detected by successive incubations with test sera, urease-conjugated rabbit-human antibody, and urease substrate. Reactive sera developed a definite and easily visualized purple color. Sera from patients with single infections of P. vivax or P. ovale were unreactive. No cross-reactivity was noted with sera from patients with rheumatoid arthritis, filariasis, amebiasis, schistosomiasis, dengue, scrub typhus, leptospirosis, or toxoplasmosis. The procedure can be performed at room temperature and completed within 1 hr. The sensitivity of the assay is comparable to that of the indirect fluorescent antibody test at all but the lowest dilutions tested.
Lee
M
M
Malaria Research Group, U.S. Army Medical Research Unit, Kuala Lumpur, Malaysia.
Lambros
C
C
D000818:Animals; D000913:Antibodies, Protozoan / Q000032:analysis*; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D006801:Humans; D010963:Plasmodium falciparum / Q000276:immunology*; D011237:Predictive Value of Tests; D014510:Urease
D000913:Antibodies, Protozoan; D014510:Urease