The EpiTuub® C. difficile Antigen test is a “sandwich” immunoassay utilizing two monoclonal antibodies to specifically detect the presence of C. difficile in feces. It consists of two units, a fecal sampling device and a test strip. A stool specimen is collected into the sampling tube containing extraction solution. After mixing the stool sample, a test strip is screwed into the sampling tube by breaking the bottom seal of the sampling tube while maintaining a vertical position. The extracted fecal solution flows into the bottom space of the test strip and triggers the start of the C. difficile immunoassay. If C. difficile is present in a fecal sample extract, an immuno-complex of “labeled monoclonal anti- C. difficile antibody – membrane coated monoclonal anti-human C. difficile antibody” is formed. A red colored band appears in the test region, which is located in the lower half of the test membrane. A green colored band must appear in the control region located in the upper half of the test membrane, indicating the test strip is functioning properly and the result is valid.