Anti-VZV IgG and IgG avidity ELISA kit, 48 tests

 

This assay is a solid-phase immuno-analytical test. The polystyrene strips are coated with a native antigen containing immunodominant epitopes of VZV. Serum samples are applied into two parallel wells and the anti-VZV antibodies present in the samples bind to the immobilized antigens. One well is incubated with the wash buffer and the parallel well is incubated with the urea solution. Antibodies with low and high avidity remain bound to the antigen in the first well, whereas in the second well the low avidity antibodies are released due to the high concentration of urea. The bound antibodies are recognized by animal antihuman IgG antibodies labeled with horseradish peroxidase. The amount of the bound labeled antibodies is revealed by an enzymatic reaction that leads to a color change. The presence of the low avidity antibodies is indicated by a drop of absorbance in wells in which the urea solution was added. The ratio between the optical density of the well without urea and the corresponding well with urea represents the relative avidity index.