Journal: PLoS Neglected Tropical Diseases

Article Title: Detection of Serotype-Specific Antibodies to the Four Dengue Viruses Using an Immune Complex Binding (ICB) ELISA

doi: 10.1371/journal.pntd.0002580

Figure Lengend Snippet: A : During incubation of serum samples containing antibody (AB) and POD-labeled recombinant antigen (POD, AG) immune complexes form, which in turn are attached to the solid-phase coated with CD32. Non-specific antibodies (in grey) do neither bind to the antigen nor to CD32. Competition with unlabeled antigen is not shown. B : Schematic drawing of the POD-labeled EDIII domain of DENV-2 (DeP2) and of the unlabeled EDIII domain of DENV-3 (De3) serving as competitor in the ICB-ELISA. While type-specific epitopes on the DeP2 and De3 are different from each other, cross-reacting epitopes are almost identical. In the presence of an excess of De3, cross-reacting antibodies will no longer bind to sub-domain epitopes on the DeP2 antigen. Amino acids (aa) involved in epitope formation are also indicated. Of note, a subcomplex (aa 305,307) and a type-specific (aa 303,304) epitope are in close proximity.

Article Snippet: Intra- and interassay coefficients of variation (CVs) were calculated for each ICB ELISA ((Prism 6 Package, GraphPad Software, Inc., San Diego, CA) using our four positive control sera in rows of sixfold, tested on three consecutive days.

Techniques: Incubation, Labeling, Recombinant, Enzyme-linked Immunosorbent Assay