Test library
Interferon Gamma Release Assay TB Test
The TB Gold blood test, also called QuantiFERON, uses a blood sample to check for tuberculosis infection by measuring the immune response to TB proteins. It can detect latent or active infection without a skin test.
Order TB Gold Blood Test
Order online and visit a local collection site, or choose an at-home kit where available. No referral and no insurance required.
Order TB Gold Blood Test- Typical turnaround
- 1-3 business days
- Starting price
- From $199
- Results
- Confidential, online
Quick answer
The TB Gold blood test, commonly known as QuantiFERON, checks whether a person has been infected with the bacteria that cause tuberculosis. It works by measuring the immune system's response to specific TB proteins in a blood sample. Unlike a skin test, it needs only one visit and no second reading. Results help clinicians evaluate latent or active TB infection.
What this test measures
Tuberculosis is caused by Mycobacterium tuberculosis, a bacterium that usually affects the lungs and can remain inactive for years. The QuantiFERON assay measures interferon-gamma released by white blood cells when they encounter TB-specific antigens. This immune response indicates prior exposure to the bacterium. Clinicians use the result alongside symptoms, imaging, and other tests when evaluating possible latent or active infection.
The sample is whole blood collected into specialized tubes that contain TB antigens, a negative control, and a positive control. After incubation, the laboratory measures interferon-gamma in the plasma. The assay targets antigens such as ESAT-6 and CFP-10, which are absent from most BCG vaccine strains and from many non-tuberculous mycobacteria, which improves specificity compared with older skin testing.
The test is often requested for people who have had close contact with someone with active TB, for healthcare and congregate-setting workers, for people starting certain biologic treatments, and for those born or living in regions where TB is more common. It is a screening tool and does not by itself confirm active disease, so a qualified healthcare provider interprets it with the full clinical picture.
- Interferon-gamma response to TB antigens
- ESAT-6 antigen response
- CFP-10 antigen response
- TB antigen tube interferon-gamma level
- Nil (negative control) value
- Mitogen (positive control) value
- Qualitative QuantiFERON result (positive, negative, indeterminate)
Why people order this test
- Evaluate possible exposure to tuberculosis
- Screen before starting certain biologic treatments
- Test healthcare and congregate-setting workers
- Follow up after close contact with active TB
- Assess people from regions where TB is more common
- Provide a single-visit alternative to skin testing
How to prepare
No fasting is required for this blood test. Follow the laboratory's collection instructions, and let the collector know about any current medications or immune conditions that could affect the response.
Understanding your results
Results are typically available within one to three business days. A positive result suggests infection with the TB bacterium, while an indeterminate result may require a repeat sample. A qualified healthcare provider interprets the report alongside symptoms, imaging, and other testing.
Interferon Gamma Release Assay TB Test by state
Alabama
Interferon Gamma Release Assay TB Test across Alabama.
Alaska
Interferon Gamma Release Assay TB Test across Alaska.
Arizona
Interferon Gamma Release Assay TB Test across Arizona.
Arkansas
Interferon Gamma Release Assay TB Test across Arkansas.
California
Interferon Gamma Release Assay TB Test across California.
Colorado
Interferon Gamma Release Assay TB Test across Colorado.
Connecticut
Interferon Gamma Release Assay TB Test across Connecticut.
Delaware
Interferon Gamma Release Assay TB Test across Delaware.
Florida
Interferon Gamma Release Assay TB Test across Florida.
Georgia
Interferon Gamma Release Assay TB Test across Georgia.
Hawaii
Interferon Gamma Release Assay TB Test across Hawaii.
Idaho
Interferon Gamma Release Assay TB Test across Idaho.
Related tests
12 Panel Drug Test (Drugs of Abuse Testing), Hair
Compare 12 Panel Drug Test (Drugs of Abuse Testing), Hair options and order online.
12 Panel Drug Testing
Compare 12 Panel Drug Testing options and order online.
7 Panel Drug Test (Drugs of Abuse Testing), Hair
Compare 7 Panel Drug Test (Drugs of Abuse Testing), Hair options and order online.
9 Panel Drug Test
Compare 9 Panel Drug Test options and order online.
9 Panel Drug Test (Drugs of Abuse Testing), Hair
Compare 9 Panel Drug Test (Drugs of Abuse Testing), Hair options and order online.
Frequently Asked Questions
What does the TB Gold blood test measure?
It measures the release of interferon-gamma by white blood cells after they are exposed to TB-specific antigens, which indicates an immune response to the tuberculosis bacterium.
How is this different from a TB skin test?
The blood test needs only one visit and no follow-up reading, and it is not affected by prior BCG vaccination the way a skin test can be.
Does a positive result mean I have active tuberculosis?
Not necessarily. A positive result indicates infection with the bacterium, which may be latent or active. A healthcare provider uses symptoms, imaging, and other tests to tell the difference.
Can the test tell if TB is latent or active?
No. The assay indicates whether infection is present but does not distinguish between latent and active disease. Additional clinical evaluation is needed.
Do I need to fast before the test?
Fasting is not required. A blood sample is collected, and the timing of the collection does not affect this test.
Ready to get tested?
Order online and visit a collection site near you, or choose a mail-in kit. No referral and no insurance required.
Reviewed by the LabOrdering Editorial Team
Every page on this site is reviewed for clarity, sourcing, and accuracy. We update our library as testing options, collection networks, and accreditation standards change.