The H.Pylori Antigen Test is a lateral flow chromatographic immunoassay based on the principle of the double antibody–sandwich technique. The test cassette consists of: 1) a purple-colored conjugate pad containing H. Pylori antibody conjugated with colloidal gold (H. Pylori conjugates) 2) a nitrocellulose membrane strip containing a test line (T line) and a control line (C line). The T line is pre-coated with non-conjugated H. Pylori antibody, and the C line is pre-coated with goat anti-mouse IgG. When an adequate volume of test specimen is dispensed into the sample well of the cassette, the specimen migrates by capillary action across the cassette. The antigen of H. Pylori if present in the specimen will bind to the H. Pylori conjugates. The immunocomplex is then captured on the membrane by the pre-coated H. Pylori antibody, forming a pink-colored T line, indicating a H. Pylori Ag positive test result.

      To serve as a procedural control, a colored line will always appear in the control region indicating that proper volume of specimen has been added and membrane wicking has occurred. Otherwise, the test result is invalid and the specimen must be retested with another device.