Mycobacterium tuberculosis Nucleic Acid Amplification (NAA)

Use of Test

Direct detection of Mycobacterium tuberculosis DNA in sediments prepared from sputum, bronchial specimens, or tracheal aspirates

Test Includes

Polymerase chain reaction (PCR)

Availability

Test is available to all clinical laboratories and local public health jurisdictions; advance notification is requested prior to shipment of specimen

For related testing options, see “Mycobacterium species Culture (Clinical Material)”

Limitations

The assay is specific for members of the Mycobacterium tuberculosis complex, but does not differentiate the members within the complex. The assay should always be performed with culture. This test is for patients who have received no antituberculous therapy, less than 7 days of such therapy, or have not received such therapy in the past 12 months.

If submitting sediments, they must be prepared by the NALC-NaOH digestion/decontamination procedure and resuspended in a 67mM concentration of phosphate buffer.

Fees

Public health investigation testing - Exempt
Non-public health investigation testing - Exempt

Causes for Rejection

Inappropriate specimen transport container; Unlabeled or mislabeled specimen; Inappropriate transport conditions; Incomplete or missing specimen submission form; Specimen leakage during transport; Inappropriate specimen for test ordered; Specimen outdated, exceeds appropriate time from collection to receipt; Quantity not sufficient to perform test; Improperly preserved specimen; Grossly bloody specimen

Turnaround Time

2 days

Forms Required

Microbiology Submission Form (HEA 2530)

Specimen Requirements

Unprocessed: A minimum of 5 mL of sputum, bronchial specimen, or tracheal aspirate maintained at 2-8°C and received within 7 days of collection.

Processed sediment: A minimum of 500 μL frozen at -70°C immediately after processing. Alternatively, maintain at 2-8°C and ship on cold packs to arrive within 3 days of processing. Stability - Refrigerated: 3 days; Frozen: indefinite

Collect in sterile 50mL screw-capped centrifuge tubes.

Shipping Requirements

Shipping unprocessed specimen refrigerated on cold packs is preferred, otherwise, ship overnight at ambient temperature.

Ship sediments overnight at refrigerated temperature on cold packs, otherwise, frozen on dry ice.

Ship in compliance with federal regulation and local guidelines. Refer to the Shipping Resources page for more information.