Veratox for Gliadin R5 is a sandwich enzyme-linked immunosorbent assay (S-ELISA). Gliadin is extracted from samples with a 60% ethanol solution by shaking in a shaker or rotator. The extract is diluted in Phosphate Buffered Saline (PBS) and diluted samples are added to R5 antibody-coated wells (capture antibody) where gliadin will bind to the antibody during an incubation period. Any unbound gliadin is washed away and a second antibody, which is R5 enzyme-labeled (detector antibody) is added. The detector antibody binds to the gliadin during another incubation period. Unbound enzyme-labeled antibody is washed away and a one stop substrate is added. Color develops as a result of the presence of bound-labeled antibody. A stopping reagent is added and the color of the solution is observed. Blue indicates samples containing high levels of gliadin while purple or red samples contain little or no gliadin. The optical densities of the controls form a standard curve, and the sample optical densities are plotted against the curve to calculate the exact concentration of gliadin in parts per million (ppm).
