Test Catalog

Test Id : MCRNA

Chlamydia trachomatis, Miscellaneous Sites, Nucleic Acid Amplification, Varies

Useful For
Suggests clinical disorders or settings where the test may be helpful

Detecting Chlamydia trachomatis in non-US Food and Drug Administration-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 or other Chlamydia species

Method Name
A short description of the method used to perform the test

Transcription Mediated Amplification

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

C. trach, Misc, Amplified RNA

Lists additional common names for a test, as an aid in searching

Chlamydia trachomatis DNA Probe

Chlamydia trachomatis RNA amplification

Specimen Type
Describes the specimen type validated for testing


Ordering Guidance

This test is used for specimens that are not US Food and Drug Administration (FDA) approved for this assay. Acceptable non-FDA-approved specimen types are ocular swabs, nasopharyngeal swabs, and peritoneal fluid.


New York State Clients: Nasopharyngeal swabs are not an approved specimen source for NY state. Testing will be canceled on NP swab specimens received from NY state.


For FDA-approved specimen types, order CTRNA / Chlamydia trachomatis, Nucleic Acid Amplification, Varies.

Necessary Information

Specimen source is required.


Question ID Description Answers

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Submit only 1 of the following specimens:


Specimen Type: Ocular (corneal/conjunctiva)

Pediatric Specimen Type: Nasopharyngeal (NP: only acceptable for patients 6 months old or younger. Note: This is not an approved source for New York state clients)


Swab, Aptima Male/Female Collection (T583) (also known as Aptima Collection Unisex Swab)

Swab, Aptima Multitest Swab Specimen Collection Kit (T584)

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

Specimen Volume: Swab

Collection Instructions:

1. Swab site using Aptima Multitest Swab or Aptima Collection Unisex Swab. Specimens must be collected using either of these Aptima swabs.

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 and store swab container (refrigerate temperature is preferred) within 60 days of collection.


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

Supplies: Aptima Thin Prep Transport Tube (T652)

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 (refrigerate temperature is preferred) within 30 days of collection.


Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

See Specimen Required

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

 All specimens will be evaluated at Mayo Clinic Laboratories for test suitability

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

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

Useful For
Suggests clinical disorders or settings where the test may be helpful

Detecting Chlamydia trachomatis in non-US Food and Drug Administration-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 or other Chlamydia species

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Chlamydia is caused by the obligate intracellular bacterium Chlamydia trachomatis and is the most prevalent sexually transmitted infection (STI) caused by bacteria in the United States. In 2020, over 1.5 million documented cases were reported to the Centers for Disease Control and Prevention (CDC). Given that 3 out of 4 infected women and 1 out of 2 infected men are initially asymptomatic, the actual prevalence of disease is thought to be much greater than reported. C trachomatis 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. 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 in the newborn. 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 25 years of age 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. 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, although residual nucleic acid may remain in the absence of active infection.


Improved screening rates and increased sensitivity of nucleic acid amplification testing have resulted in an increased number of accurately diagnosed cases. Improved detection rates result from improved performance characteristics of the assays and 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
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.


Provides information to assist in interpretation of the test results

A positive result indicates the presence of nucleic acid from Chlamydia trachomatis.


A negative result indicates the absence of C trachomatis nucleic acid. A negative result does not exclude the possibility of infection. If clinical indications strongly suggest chlamydial infection, additional specimens should be collected for testing.


A result of indeterminate indicates that a new specimen should be collected.


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

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

This report is intended for clinical monitoring or management of patients; it is not intended for use in medico-legal applications.


Appropriate specimen collection and handling is necessary for optimal assay performance.


Results should be interpreted in conjunction with other laboratory and clinical information.


A negative test result does not exclude the possibility of infection. Improper specimen collection, concurrent antibiotic therapy, presence of inhibitors, or low numbers of organisms in the specimen (ie, below the sensitivity of the test) may cause false-negative test results.


In low-prevalence populations, positive results must be interpreted carefully as false-positive results may occur more frequently than true-positive results in this setting.


In general, this assay should not be used to assess therapeutic success or failure, since nucleic acids from this organism may persist for 3 weeks or more following antimicrobial therapy.


No interference is expected with swab specimens due to:


-Lubricants and spermicides


This assay does not detect Chlamydia pneumoniae or other Chlamydia species

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Workowski KA, Bachmann LH, Chan PA, et al: Sexually transmitted infections treatment guidelines, 2021. MMWR Recomm Rep. 2021 Jul 23;70(4):1-187. doi: 10.15585/mmwr.rr7004a1

2. Adamson PC, Klausner JD: Diagnostic test for detecting Chlamydia trachomatis and Neisseria gonorrhoeae in rectal and pharyngeal specimens. J Clin Microbiol. 2022 Apr 20;60(4):e0021121. doi: 10.1128/JCM.00211-21

Method Description
Describes how the test is performed and provides a method-specific reference

The Hologic Aptima Combo 2 Assay combines the technologies of target capture, transcription-mediated amplification, and dual kinetic assay. The detection of the ribosomal RNA amplification product sequences (amplicon) is achieved using nucleic acid hybridization. Single-stranded chemiluminescent DNA probes are labeled and combined with amplicon to form stable RNA:DNA hybrids. Light emitted from the labeled RNA:DNA hybrids is measured as photon signals in a luminometer.(Package insert: APTIMA Combo 2 Assay, 20535-001. Hologic, Inc; Rev 004, 08/2021)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Sunday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

1 to 4 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

7 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

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
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.


LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
MCRNA C. trach, Misc, Amplified RNA 43304-5
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
SRC11 SOURCE: 31208-2
34507 C. trach, Misc, Amplified RNA 43304-5

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports

Test Update Resources

Change Type Effective Date
Test Status - Test Resumed 2022-03-03
Test Status - Test Delay 2021-12-02