The Clostridium difficile Toxin/Antitoxin Kit is intended for use in conjunction with the tissue culture cytotoxicity assay for the confirmation of Clostridium difficile toxin in patient specimens. The kit includes a toxin control reagent and a specific C. difficile antitoxin for use in a tissue culture assay. The test is to be used as an aid in the diagnosis of C. difficile disease and results should be considered in conjunction with the patient history.