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Test Code CDTP C. difficile Assay by PCR

Infectious

Additional Codes

CDTPB

Specimen and Container/Tube

Specimen Type: Unformed stool

Preferred Specimen: Sterile, sealable, screw-cap container

Specimen Stability

Storage Temperature

Stability

Room temperature

(20 - 30°C)

2 days

Refrigerated

(2 - 8°C)

7 days

Frozen

(-20°C)

60 days

Collection Instructions

Specimen Collection: Use one polyester swab to transfer stool into the cobas® PCR Media tube. If stool was collected in bedpan, must not be contaminated with urine, residual soap, or disinfectant.

Specimen Transport: Immediate

Specimen Handling and Transport Instructions

UCMC Onsite Instructions: Collect specimen per standard collection procedure and send to laboratory immediately. 

 

UCMC Offsite and UC MedLab Outreach Instructions: Collect specimen per standard collection procedure and send to laboratory immediately. If transport is delayed, refrigerate specimens prior to transport, if applicable to specimen type.

Rejection Criteria

  • Common specimen rejected situations include: incorrect specimen type, insufficient volume, incorrect collection container, missing or incomplete specimen identifiers, incorrect specimen transport, or specimens outside stability limits. 
  • Formed stools will be rejected.

Reference Values

 

Test

Age

Sex

Reference Range
Toxigenic C. difficile DNA

All

All

Negative

Turnaround Time

Turnaround times are relative to the time the specimen is received in the test laboratory. 

STAT Turnaround Time: not available

Routine Turnaround Time: 3 hours

Testing Schedule: Monday - Sunday

Clinical Indications

  • Aid in the diagnosis of C. difficile infection in humans in conjunction with clinical and epidemiological risk factors.
  • A positive result is indicative of the presence of toxigenic C. difficile DNA and not necessarily viable organisms. Therefore, a positive result does not necessarily mean eradication or treatment failure.

CPT Codes

87493

LOINC Codes

30687493

Methodology

Automated real-time polymerase chain reaction (PCR)

Synonyms/Keyword Search

C DIFF, C DIF, CDIFF, C.DIFF

Last Review Date

10/24/2025