Diagnostic Test Directory

Microbiology Laboratory

Rapid Clostridium difficile Toxin

  • LIS Mnemonic: CDTAG


    Unformed (soft or liquid) stool/feces specimens collected in a sterile, leak-proof container.

    Stool should ONLY be submitted for patients >12 months old.

    Volume Required

    1-2 mLs

    Minimum Required

    1 mL


    Send to the lab immediately at room temperature. If transport is delayed, refrigerate or freeze specimen and send on ice.


    1 hour at room temperature; 1 to 24 hours refrigerated; if more than 24 hours, specimen must be frozen.

    Unacceptable conditions

    Formed stool, specimens sent on swabs, and diapers containing stool are not acceptable specimens for this test. Stool submitted on children <12 months old will not be accepted. Washings (colonic, duodenal, etc) will not be accepted due to their possible dilution factor. Specimens containing barium should not be submitted.

Days Performed



2 hour expected turn-around time from receipt in lab

Reflex Testing

If the GDH antigen screen is found indeterminate, testing will reflex to Illumigene® testing for confirmation of specimen.


87324 (GDH antigen screen); 87493 (Illumigene®)


GDH antigen screen: membrane enzyme immunoassay; Confirmatory testing: loop-mediated isothermal DNA amplification (LAMP)