Gonorrhea-Chlamydia (GC-CT)

Gonorrhea/Chlamydia (GC/CT), Amplified RNA Probe

Laboratory Fee Schedule
Procedure: MBB0191A
CPT: 87491, 87591

Synonym(s): Gonorrhea/Chlamydia (GC/CT), Amplified RNA Probe
Requisition Form G-2B
Test Description Target amplification nucleic acid probe test that utilizes target capture for qualitative detection and differentiation of ribosomal RNA (rRNA) from Chlamydia trachomatis (CT) and/or Neisseria gonorrhea (GC)
Pre-Approval Needed N/A
Supplemental Information Required N/A
Supplemental Form(s) N/A
Performed on Specimens from (sources) Human
Sample/Specimen Type for Testing
  • Vaginal swabs- Aptima Multitest Swab Collection Kit
  • Endocervical-Aptima Unisex swabs Collection Kit
  • Urethral swabs- Aptima Unisex swabs Collection Kit
  • Urine specimens-Aptima Urine Collection Kit
  • Oral-Aptima Multitest Swab Collection Kit
  • Rectal- Aptima Multitest Swab Collection Kit
  • Nasopharyngeal- Aptima Multitest Swab Collection Kit
  • Penile Meatal- Aptima Multitest Swab collection Kit
Minimum Volume/Size Required One correct swab or urine filled between the two black indicator lines on the tube label
Storage/Preservation Prior to Shipping


  • Store in a specimen transport tube at 2°C to 30°C for up to 60 days
  • Extragenital (rectal and oral) store  at 4-30°C for up to 60 days
  • For long term storage is needed, freeze at -20°C to -70°C. 


  • Store in urine specimen in a transport tube at 2°C to 30°C for up to 30 days
  • For long term storage, freeze at -20°C to -70°C. 
Transport Medium N/A
Specimen Labeling
  • Two patient-specific identifiers required (e.g., patient full name, date of birth, Medical record number)
  • Identifiers on specimen must exactly match submission form.
Shipping and Specimen Handling Requirements
  • Ship according to Dangerous Goods Regulations, IATA, and/or CFR 49.
  • Handle as infectious agent using universal precautions.
  • Triple contain in accordance with federal shipping regulations for infectious agents.  
    Additional forms & resources
Method Target amplification nucleic acid probe test
Turn-around Time 3 working days
Interferences/Limitations Reliable results are dependent on adequate specimen collection.
Common Causes for Rejection
  • Unacceptable specimen type or source
  • Improper shipping conditions
  • Expired media or collection container
  • Discrepancies between specimen label and/or submission form
  • Incomplete or missing submission form
  • Wrong swab submitted (white)
  • No swab
  • Two swabs
  • A swab not supplied by Gen-Probe
  • Urine not filled between the two black indicator lines on tube label.
Additional Information Results from the APTIMA COMBO 2 Assay should be interpreted in conjunction with other laboratory and clinical data available to the clinician.