How the Test is Performed

A sample of body fluid or tissue is needed. This may be taken from the lungs, liver, or bone marrow.

Most often, you will be asked to cough deeply and spit out the material that comes up from your lungs, called sputum.

A biopsy or aspiration may also be done.

The sample is placed in a special laboratory dish (culture media) and watched to see if the bacteria that causes TB grows.

How to Prepare for the Test

The preparation depends on how the test is done.

For details, see:

• Bone marrow aspiration
• Liver biopsy
• Lung biopsy

How the Test Will Feel

How the test will feel depends on the specific procedure.

For details, see:

• Bone marrow aspiration
• Liver biopsy
• Lung biopsy

Why the Test is Performed

Your doctor may order this test if you have signs of tuberculosis or a related infection.

Normal Results

If there is no disease present, there will be no growth of bacteria in the culture medium.

What Abnormal Results Mean

Mycobacterium tuberculosis or similar bacteria is present in the culture.

Risks

Risks depend on the specific biopsy or aspiration being performed. There are no risks associated with the culture itself.

Alternative Names

Culture - mycobacterial

References

Iseman MD. Tuberculosis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 345.

Ellner JJ.Tuberculosis. In: Goldman L, Schafer AI, eds.Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 332.

Updated: 4/6/2012

Reviewed by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School, Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.