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Test Code CHGC Chlamydia/GC, Nucleic Acid Method (NAM)

Useful For

Detection of Chlamydia trachomatis and Neisseria gonorrhoeae directly from urine, female endocervical swabs, and Thin Prep samples. Male and female rectal, throat swab specimens.

Synonyms/Keywords

Chlamydia/GC Nucleic Acid

Specimen Requirements

Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)

Urine - First catch

APTIMA urine specimen transport tube (Yellow labeled tube)

   20.0-30.0 mL 2.0 mL  
Cervical Swab APTIMA multitest pink shaft collection swab (Orange labeled tube)     1 swab  
Vaginal Swab APTIMA multitest pink shaft collection swab (Orange labeled tube)     1 swab  
Rectal Swab APTIMA multitest pink shaft collection swab (Orange labeled tube)     1 swab  
Throat Swab APTIMA multitest pink shaft collection swab (Orange labeled tube)     1 swab  

Collection/Processing Instructions

This test will not be performed on prepubescent children or for medico-legal situations. Please refer to Chlamydia culture in these circumstances.  

 

  1. Male and female urine specimens transported in APTIMA urine specimen (yellow label) transport tube. Collect 20-30 ml of first catch urine (the first part of the stream).  Patient should not have urinated for at least 1 hour prior to specimen collection.  Transfer 2 ml of first-catch urine to APTIMA urine specimen tube.  Urine samples must be transferred to an APTIMA urine specimen tube within 24 hours of collection.  
  2. Endocervical specimens from asymptomatic or symptomatic patients submitted in an APTIMA multitest (orange label) collection tube. 
  3. Vaginal specimens from asymptomatic or symptomatic patients submitted in an APTIMA multitest (orange label) tube using the pink shaft swab. Specimen(s) are provider collected or patient collected in provider's office after thorough instructions.  
  4. PreservCyt Thin Prep solution vial - see Cytology, PAP, Thin Prep for collection requirements.  
  5. Rectal specimens from asymptomatic or symptomatic patients submitted in an APTIMA multitest (Orange label) tube using the pink shaft swab.
  6. Throat specimens from asymptomatic or symptomatic patients submitted in an APTIMA multitest (Orange label) tube using the pink shaft swab.  

 

Collection Procedure Guides:

Urine Collection

Clinician Collected Vaginal Swab

 

For more information on Specimen Collection Media/Swab, see Specimen Transport Pictorial.  

Specimen Stability Information

Specimen Type Temperature Time
APTIMA urine specimen transport tube (yellow label) Ambient or Refrigerate 30 days
APTIMA Vaginal pink shaft swab (orange label) Ambient or Refrigerate 60 days
PreservCyt solution vial Ambient 2 weeks
PreservCyt solution vial Refrigerate 30 days

Rejection Criteria

Improper specimen source (Eye)
Pre-pubescent children or Medico-Legal Cases
Female urethral swabs
Overfilling/underfilling of the APTIMA urine transport tube
Volumes < 2 mL
Volumes > 30 mL
Non-Aptima Swabs

Test Components

CH-NAM, Chlamydia Trachomatis, Nucleic Acid Method (NAM)
GC-NAM, Neisseria Gonorrhoeae, Nucleic Acid Method (NAM)

Test Information

The following applies to female urine sources:

This test was developed and its performance characteristics determined by Marshfield Labs. This laboratory is certified under the Clinical Laboratory Improvement Amendments (CLIA) to perform high complexity testing.

 

This test cannot be utilized in medico-legal situations or prepubescent children. 

 

Culture is the recommended method in these cases and for rejected sample types listed in the rejection criteria section.

Interpretations

Reported as Negative, Positive, Indeterminate or Equivocal for Chlamydia trachomatis and Neisseria gonorrhoeae RNA by TMA. Equivocal results are inconclusive.  Repeat testing with a  new specimen is recommended. Indeterminate results are due to unidentified interference. Repeat testing with a new specimen is recommended.

Reference Range Information

Performing Location Reference Range
Marshfield

Negative for N. gonorrhoeae RNA by TMA 

Negative for Chlamydia trachomatis RNA by TMA.

Marshfield Labs Performing Department

Marshfield Labs Molecular Pathology

Performing Information

Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Marshfield Monday - Friday 1 day Transcription-Mediated Amplification (TMA)

Outreach CPT Codes

CPT Modifier
(if needed)		 Quantity Description Comments
87591     Neisseria, amplified probe  
87491     Chlamydia, amplified probe