Sign in →

Test ID: MCTGC Chlamydia trachomatis and Neisseria gonorrhoeae, Miscellaneous Sites, Nucleic Acid Amplification, Varies

Useful For

Detection of Chlamydia trachomatis and Neisseria gonorrhoeae in non-FDA-approved specimen types


This test is not intended for use in medico-legal applications.


This test is not useful for the detection of Chlamydia pneumoniae.

Profile Information

Test ID Reporting Name Available Separately Always Performed
MCRNA C. trach, Misc, Amplified RNA Yes Yes
MGRNA N. gonorr, Misc, Amplified RNA Yes Yes

Method Name

Transcription Mediated Amplification

Reporting Name

Misc C trach/N gonor Amplified RNA

Specimen Type


Ordering Guidance

This test is used for specimens that are not FDA approved for this assay. Acceptable non-FDA-approved specimen types are ocular swabs, and peritoneal fluid. For FDA-approved specimen types, order CGRNA / Chlamydia trachomatis and Neisseria gonorrhoeae, Nucleic Acid Amplification, Varies.

Necessary Information

Specimen source is required.

Specimen Required

Swab specimens must be collected using an Aptima Collection Unisex Swab (T583), or Aptima Collection Multitest Swab (T584). These swabs are contained in the Aptima Collection Kit.


Submit only 1 of the following specimens:



Swab, Aptima Male/Female Collection (T583)

Swab, Aptima Multitest Swab Specimen Collection Kit (T584)

Specimen Type: Ocular (corneal/conjunctiva)

Container/Tube: Aptima Collection Multitest Swab or Aptima Swab Collection System

Specimen Volume: Swab

Collection Instructions:

1. Swab site using Aptima Collection Multitest Swab or Aptima Collection Unisex Swab.

Note: The white swab provided within the collection kit is a cleaning swab and should not be used for collection. Discard the white cleaning swab.

2. Place collection swab in transport tube provided in collection kit. Snap off swab at score line so swab fits into closed tube.

3. Cap tube securely and label tube with patient's entire name and collection date and time.

4. Transport swab container and store (refrigerated is preferred) within 60 days of collection.


Supplies: Aptima Thin Prep Transport Tube (T652)

Specimen Type: Peritoneal fluid (pelvic wash, cul-de-sac fluid)

Container/Tube: Aptima Specimen Transfer Tube

Specimen Volume: 1 mL

Collection Instructions:

1. Transfer specimen into the Aptima Specimen Transfer Tube within 24 hours of collection.

2. Cap tube securely and label tube with patient's entire name and collection date and time.

3. Transport Aptima Specimen Transfer Tube (refrigerated is preferred) within 30 days of collection.

Specimen Minimum Volume

See Specimen Required

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Refrigerated (preferred) APTIMA VIAL
  Ambient  APTIMA VIAL

Clinical Information

Chlamydia is caused by the obligate intracellular bacterium Chlamydia trachomatis and is the most prevalent sexually transmitted bacterial infection in the United States.(1,2) In 2010, 1.3 million documented cases were reported to the CDC.(2) Given that 3 out of 4 infected women and 1 out of 2 infected men will be asymptomatic initially, the actual prevalence of disease is thought to be much greater than reported. The organism causes genitourinary infections in women and men and may be associated with dysuria as well as vaginal, urethral, or rectal discharge. In women, complications include pelvic inflammatory disease, salpingitis, and infertility. Approximately 25% to 30% of women who develop acute salpingitis become infertile.(2) Complications among men are rare but include epididymitis and sterility. Rarely, genital chlamydial infection can cause arthritis with associated skin lesions and ocular inflammation (Reiter syndrome). C trachomatis can be transmitted from the mother during delivery and is associated with conjunctivitis and pneumonia. Finally, C trachomatis may cause hepatitis and pharyngitis in adults.


Once detected, the infection is easily treated by a short course of antibiotic therapy. Annual chlamydia screening is now recommended for all sexually active women age 25 years and younger and for older women with risk factors for infection, such as a new sex partner or multiple sex partners. The CDC also recommends that all pregnant women be given a screening test for Chlamydia infection.(2) Repeat testing for test-of-cure is not recommended after treatment with a standard treatment regimen unless patient compliance is in question, reinfection is suspected, or the patient's symptoms persist. Repeat testing of pregnant women, 3 weeks after completion of therapy, is also recommended to ensure therapeutic cure.(2)


Gonorrhea is caused by the bacterium Neisseria gonorrhoeae. It is also a very common sexually transmitted infection (STI), with 301,174 cases of gonorrhea reported to CDC in 2009.(2,3) Many infections in women are asymptomatic and the true prevalence of gonorrhea is likely much higher than reported. The organism causes genitourinary infections in women and men and may be associated with dysuria as well as vaginal, urethral, or rectal discharge. Complications include pelvic inflammatory disease in women and gonococcal epididymitis and prostatitis in men. Gonococcal bacteremia, pharyngitis, and arthritis may also occur. Infection in men is typically associated with symptoms that would prompt clinical evaluation. Given the risk for asymptomatic infection in women, screening is recommended for women at increased risk of infection (eg, women with previous gonorrhea or other STI, inconsistent condom use, new or multiple sex partners, and women in certain demographic groups such as those in communities with high STI prevalence).(2,3) The CDC currently recommends dual antibiotic treatment due to emerging antimicrobial resistance.(2)


Culture was previously considered to be the gold standard test for diagnosis of C trachomatis and N gonorrhoeae infections.(2) However, organisms are labile in vitro, therefore, precise specimen collection, transportation, and processing conditions are required to maintain organism viability, which is necessary for successful culturing. In comparison, nucleic acid amplification testing (NAAT) provides superior sensitivity and specificity and is now the recommended method for diagnosis in most cases.(4-6) Immunoassays and non-amplification DNA tests are also available for C trachomatis and N gonorrhoeae detection, but these methods are significantly less sensitive and less specific than NAAT.(2)


Improved screening rates and increased sensitivity of NAAT testing have resulted in an increased number of accurately diagnosed cases of both chlamydia and gonorrhea.(2-6) Improved detection rates result from both the increased performance of the assay and the patients' easy acceptance of urine testing. Early identification of infection enables sexual partners to seek testing and/or treatment as soon as possible and reduces the risk of disease spread. Prompt treatment reduces the risk of infertility in women.

Reference Values



A positive result indicates that rRNA of Chlamydia trachomatis and/or Neisseria gonorrhoeae is present in the specimen tested and strongly supports a diagnosis of chlamydial/gonorrheal infection.


A negative result indicates that rRNA for C trachomatis and/or N gonorrhoeae was not detected in the specimen.


The predictive value of an assay depends on the prevalence of the disease in any particular population. In settings with a high prevalence of sexually transmitted disease, positive assay results have a high likelihood of being true positives. In settings with a low prevalence of sexually transmitted disease, or in any setting in which a patient's clinical signs and symptoms or risk factors are inconsistent with gonococcal or chlamydial urogenital infection, positive results should be carefully assessed and the patient retested by other methods (eg, culture for N gonorrhoeae), if appropriate.


A negative result does not exclude the possibility of infection. If clinical indications strongly suggest gonococcal or chlamydial infection, additional specimens should be collected for testing. A result of indeterminate indicates that a new specimen should be collected.


This test has not been shown to cross react with commensal (nonpathogenic) Neisseria species present in the oropharynx.

Clinical Reference

1. Centers for Disease Control and Prevention. 2014. Recommendations for the laboratory-based detection of Chlamydia trachomatis and Neisseria gonorrhoeae, 2014. MMWR Morb Mortal Wkly Rep. 2014;63:1-18

2. Centers for Disease Control and Prevention: Sexually Transmitted Diseases Treatment Guidelines, 2015. MMWR Morb Mortal Wkly Rep. 2015 Jun 5;64(RR-03):1-137.

3. Centers for Disease Control and Prevention. 2002. Reporting of laboratory-confirmed chlamydial infection and gonorrhea by providers affiliated with three large Managed Care Organizations-United States, 1995-1999. MMWR Morb Mortal Wkly Rep. 2002;51:256-259

4. Crotchfelt KA, Pare B, Gaydos C, Quinn TC: Detection of Chlamydia trachomatis by the GEN-PROBE AMPLIFIED Chlamydia trachomatis Assay (AMP CT) in urine specimens from men and women and endocervical specimens from women. J Clin Microbiol. 1998 Feb;36(2):391-394

5. Gaydos CA, Quinn TC, Willis D, et al: Performance of the APTIMA Combo 2 assay for detection of Chlamydia trachomatis and Neisseria gonorrhoeae in female urine and endocervical swab specimens. J Clin Microbiol. 2003 Jan;41(1):304-309

6. Chernesky MA, Jang DE: APTIMA transcription-mediated amplification assays for Chlamydia trachomatis and Neisseria gonorrhoeae. Expert Rev Mol Diagn. 2006 Jul;6(4):519-525

Day(s) Performed

Monday through Saturday

Report Available

1 to 4 days

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information



LOINC Code Information

Test ID Test Order Name Order LOINC Value
MCTGC Misc C trach/N gonor Amplified RNA In Process


Result ID Test Result Name Result LOINC Value
SRC11 SOURCE: 31208-2
SRC22 SOURCE: 31208-2
34507 C. trach, Misc, Amplified RNA 43304-5
34508 N. gonorr, Misc, Amplified RNA 43305-2
Mayo Clinic Laboratories | Microbiology and Infectious Disease Catalog Additional Information: