Test Catalog

Test ID: MTBRP    
Mycobacterium tuberculosis Complex, Molecular Detection, PCR

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

When this test is ordered, the reflex test may be performed and charged.

 

See Meningitis/Encephalitis Panel Algorithm in Special Instructions.

Specimen Type Describes the specimen type validated for testing

Varies

Shipping Instructions

Specimen must arrive within 7 days of collection; specimen >7 days will be rejected.

Necessary Information

Specimen source is required.

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

The high sensitivity of amplification by PCR requires the specimen to be processed in an environment in which contamination of the specimen by Mycobacterium tuberculosis DNA is unlikely.

 

If a single specimen is being shared between mycobacteria culture, acid-fast smear, and/or M tuberculosis PCR, a minimum volume of 2 mL for body fluid, 3 mL for respiratory specimen, or a pea-sized piece of tissue should be obtained. Specimen volumes less than indicated may decrease sensitivity of testing. If insufficient volume is submitted, test or tests will be canceled.

 

Preferred Specimens: Body fluid, cerebrospinal fluid (CSF), ocular fluid, respiratory (eg, bronchoalveolar lavage [BAL], bronchial washing, sputum), stool, fresh tissue, bone, bone marrow, or urine

 

Acceptable Specimens: If no fresh specimen is available, digested respiratory specimens treated with N-acetyl-L-cysteine (NALC)/NaOH are acceptable (eg, BAL, bronchial washing, respiratory fluid, sputum, or tracheal secretion), as are NALC/NaOH-treated gastric washings.

 

Submit only 1 of the following specimens:

 

Specimen Type: Body fluid

Sources: Body, bone marrow aspirate, ocular, or CSF

Container/Tube: Sterile container

Specimen Volume: 1 mL

Additional Information: Only fresh, non-NALC/NaOH-digested body fluid is acceptable.

 

Specimen Type: Gastric washing

Container/Tube: Sterile container

Specimen Volume: 2 mL

Collection Instructions: Neutralize specimen within 4 hours of collection with 20 mg of sodium carbonate per 2 mL of gastric washing.

 

Specimen Type: Respiratory

Sources: BAL, bronchial washing, or sputum

Container/Tube: Sterile container

Specimen Volume: 1 mL if only PCR ordered or 3 mL if PCR ordered with smear and culture

 

Specimen Type: Stool

Container/Tube: Sterile container

Specimen Volume: 5-10 g

Additional Information: Only fresh, non-NALC/NaOH-digested stool is acceptable.

 

Specimen Type: Tissue

Sources: Fresh tissue, bone, or bone marrow biopsy

Container/Tube: Sterile container

Specimen Volume: 5-10 mm

Collection Instructions: Keep moist with sterile water or sterile saline

Additional Information: Only fresh, non-NALC/NaOH-digested tissue is acceptable.

 

Specimen Type: Urine

Container/Tube: Sterile container

Specimen Volume: 1 mL

Collection Instructions: Collect a random urine specimen.

 

Acceptable

Specimen Type: NALC/NaOH-digested respiratory specimens

Sources: Lavage fluid, bronchial washing, gastric washing, respiratory fluid, sputum, or tracheal secretion

Container/Tube: Sterile container

Specimen Volume: 2 mL

Collection Instructions:

1. Submit digested specimen treated with NALC/NaOH.

2. Clearly indicate on container and order form that specimen is a digested specimen.

Special Instructions Library of PDFs including pertinent information and forms related to the test

Forms

If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.

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

Body fluid: 0.5 mL
Respiratory specimen-nondigested: 0.5 mL
Fresh tissue or bone: 5 mm
NALC-NaOH-digested specimen: 1 mL
Gastric washing: 1 mL
Stool: 5 g
Urine: 0.5 mL

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

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

Blood, specimen in anaerobe vial or viral transport medium (including but not limited to M4, M5, BD viral transport media, thioglycolate broth), swabs, tissues in formalin fluid, specimens >7 days old

 

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 TypeTemperatureTime
VariesRefrigerated (preferred)7 days
 Frozen 7 days