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

Laboratory Fee Schedule
Procedure:  MBB0191B      
CPT: 87494

Synonym(s):Gonorrhea, Chlamydia, Neisseria gonorrhoeae, Chlamydia trachomatis, Combo 2, GC/CT NAAT, Screen
Requisition FormG-2B
Test DescriptionTarget amplification nucleic acid probe test that utilizes target capture for the qualitative detection and differentiation of ribosomal RNA (rRNA) from Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (GC).
Pre-Approval NeededN/A
Supplemental Information RequiredN/A
Supplemental Form(s)N/A
Performed on Specimens from (sources)Human  
Sample/Specimen Type for Testing

The following specimen types may only be collected using the collection kit listed for each:

  • Vaginal swab: Aptima Multitest Swab Collection Kit
  • Endocervical swab: Aptima Unisex Swab Collection Kit
  • Urethral swab: Aptima Unisex Swab Collection Kit
  • Urine: Aptima Urine Specimen Collection Kit
  • Rectal swab: Aptima Multitest Swab Collection Kit
  • Throat swab: Aptima Multitest Swab Collection Kit
Minimum Volume/Size Required

One correct swab, or a urine collection tube filled between the two black indicator lines on the tube label.

  • Do not over- or under-fill urine collection tubes. 
     
Storage/Preservation Prior to Shipping

Endocervical, Vaginal, and Urethral Swabs

  • Store swab in transport tube at 2°C to 30°C for up to 60 days after collection.
  • For long term storage, freeze swab in transport tube at -20°C to -70°C within 7 days of collection.

Rectal and Throat Swabs

  • Store swab in transport tube at 4°C to 30°C OR at -20°C to 
    -70°C for up to 60 days.

Urine Specimens

  • Store specimen in transport tube at 2°C to 30°C for up to 30 days.
  • For long term storage, freeze at -20°C to -70°C within 7 days of collection for testing up to 12 months after collection.
Transport MediumN/A
Specimen Labeling
  • Two patient-specific identifiers required on specimen (e.g. patient full name, date of birth, medical record number)
  • Three patient identifiers are preferred.
  • Patient identifiers on specimen label must exactly match identifiers on submission form (e.g., abbreviated name on label and full name on form is not acceptable.)
  • Additional DSHS Laboratory specimen labeling guidelines available online here.
Shipping and Specimen Handling Requirements
  • Ship according to Dangerous Goods Regulations, IATA, and/or CFR 49.
  • Category B Biological Substance, UN3373 shipping requirements apply.
  • Handle as infectious agent using universal precautions.
  • Triple-contain in accordance with federal shipping regulations for infectious agents. 
  • Submitters are responsible for packaging and shipping specimens according to regulatory requirements.
  • Additional DSHS Laboratory specimen shipping guidelines online here.
MethodTarget amplification nucleic acid probe test
Turn-around Time3 working days
Interferences/Limitations
  • Reliable results are dependent on adequate specimen collection.
  • A negative result does not preclude a possible infection. .
Common Causes for Rejection
  • Unacceptable specimen type or source.
  • Improper shipping conditions.
  • Urine specimen (stored at 2°C to 30°C) older than 30 days.
  • Swab specimen older than 60 days.
  • Specimen collected using the wrong collection kit.
  • Urine specimen not transferred to transport tube.
  • No swab in transport tube.
  • Two swabs in transport tube.
  • Swab used to collect specimen not supplied by Hologic.
  • Urine not filled to between the two black indicator lines on tube label.
  • Expired reagents/media/collection container.
  • Discrepancies between G-2B submission form and specimen label.
  • Missing/incomplete/illegible submission form or label.
Additional InformationResults from the APTIMA COMBO 2 Assay should be interpreted in conjunction with other laboratory and clinical data available to the clinician.