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Lab Test Dictionary

Clostridium difficile Toxin/GDH with reflex to PCR (91664)


Immunoassay (IA)



Specimen Type


Performing Lab

Quest Diagnostics San Juan Capistrano

Epic ID


Lab Test Days


Standard TAT

1-2 Days

Collection Information

Specimen Required

1-5 g or mL Unformed Stool

Container Type

Sterile Container

Collection Instructions

Collect fresh stool in sterile, leak-proof container without media, preservative, or metal ion. For patients requiring the use of diapers, first line the diaper with clean plastic to prevent absorption. Then transfer 5 grams or 5 mL of the stool specimen from the plastic lined diaper to the sterile container. Do not submit the diaper itself. Cap securely. Do not use any preservative, media or additive.

Processing Information - Lab Use Only

Transport Temperature


Specimen Stability

Room Temp=Unacceptable; Refrigerated=72 Hours; Frozen=30 Days

Rejection Criteria

Formed stool; Stool submitted in transport media or swab; Rectal swab; Unfrozen stool >72 hours old; Received room temp

Test Volume Required

5 g or mL Unformed Stool

Minimum Test Volume

1 g or mL Unformed Stool

Included Tests

If the GDH Antigen is detected and the Toxin A and B are not detected or the GDH Antigen is not detected and the Toxin A and B are detected, 16377 Clostridium difficile Toxin B, Qualitative Real Time PCR will be performed.

CPT Codes

87449, 87324; 87493